diff options
Diffstat (limited to 'libraries/zxing/src/com/google/zxing/common')
22 files changed, 3207 insertions, 0 deletions
diff --git a/libraries/zxing/src/com/google/zxing/common/BitArray.java b/libraries/zxing/src/com/google/zxing/common/BitArray.java new file mode 100644 index 000000000..6eb0d57c6 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/BitArray.java @@ -0,0 +1,246 @@ +/*
+ * Copyright 2007 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.common;
+
+/**
+ * <p>A simple, fast array of bits, represented compactly by an array of ints internally.</p>
+ *
+ * @author Sean Owen
+ */
+public final class BitArray {
+ // I have changed these members to be public so ProGuard can inline get() and set(). Ideally
+ // they'd be private and we'd use the -allowaccessmodification flag, but Dalvik rejects the
+ // resulting binary at runtime on Android. If we find a solution to this, these should be changed
+ // back to private.
+ public int[] bits;
+ public int size;
+
+ public BitArray() {
+ this.size = 0;
+ this.bits = new int[1];
+ }
+
+ public BitArray(int size) {
+ this.size = size;
+ this.bits = makeArray(size);
+ }
+
+ public int getSize() {
+ return size;
+ }
+
+ public int getSizeInBytes() {
+ return (size + 7) >> 3;
+ }
+
+ private void ensureCapacity(int size) {
+ if (size > bits.length << 5) {
+ int[] newBits = makeArray(size);
+ System.arraycopy(bits, 0, newBits, 0, bits.length);
+ this.bits = newBits;
+ }
+ }
+
+ /**
+ * @param i bit to get
+ * @return true iff bit i is set
+ */
+ public boolean get(int i) {
+ return (bits[i >> 5] & (1 << (i & 0x1F))) != 0;
+ }
+
+ /**
+ * Sets bit i.
+ *
+ * @param i bit to set
+ */
+ public void set(int i) {
+ bits[i >> 5] |= 1 << (i & 0x1F);
+ }
+
+ /**
+ * Flips bit i.
+ *
+ * @param i bit to set
+ */
+ public void flip(int i) {
+ bits[i >> 5] ^= 1 << (i & 0x1F);
+ }
+
+ /**
+ * Sets a block of 32 bits, starting at bit i.
+ *
+ * @param i first bit to set
+ * @param newBits the new value of the next 32 bits. Note again that the least-significant bit
+ * corresponds to bit i, the next-least-significant to i+1, and so on.
+ */
+ public void setBulk(int i, int newBits) {
+ bits[i >> 5] = newBits;
+ }
+
+ /**
+ * Clears all bits (sets to false).
+ */
+ public void clear() {
+ int max = bits.length;
+ for (int i = 0; i < max; i++) {
+ bits[i] = 0;
+ }
+ }
+
+ /**
+ * Efficient method to check if a range of bits is set, or not set.
+ *
+ * @param start start of range, inclusive.
+ * @param end end of range, exclusive
+ * @param value if true, checks that bits in range are set, otherwise checks that they are not set
+ * @return true iff all bits are set or not set in range, according to value argument
+ * @throws IllegalArgumentException if end is less than or equal to start
+ */
+ public boolean isRange(int start, int end, boolean value) {
+ if (end < start) {
+ throw new IllegalArgumentException();
+ }
+ if (end == start) {
+ return true; // empty range matches
+ }
+ end--; // will be easier to treat this as the last actually set bit -- inclusive
+ int firstInt = start >> 5;
+ int lastInt = end >> 5;
+ for (int i = firstInt; i <= lastInt; i++) {
+ int firstBit = i > firstInt ? 0 : start & 0x1F;
+ int lastBit = i < lastInt ? 31 : end & 0x1F;
+ int mask;
+ if (firstBit == 0 && lastBit == 31) {
+ mask = -1;
+ } else {
+ mask = 0;
+ for (int j = firstBit; j <= lastBit; j++) {
+ mask |= 1 << j;
+ }
+ }
+
+ // Return false if we're looking for 1s and the masked bits[i] isn't all 1s (that is,
+ // equals the mask, or we're looking for 0s and the masked portion is not all 0s
+ if ((bits[i] & mask) != (value ? mask : 0)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ public void appendBit(boolean bit) {
+ ensureCapacity(size + 1);
+ if (bit) {
+ bits[size >> 5] |= (1 << (size & 0x1F));
+ }
+ size++;
+ }
+
+ /**
+ * Appends the least-significant bits, from value, in order from most-significant to
+ * least-significant. For example, appending 6 bits from 0x000001E will append the bits
+ * 0, 1, 1, 1, 1, 0 in that order.
+ */
+ public void appendBits(int value, int numBits) {
+ if (numBits < 0 || numBits > 32) {
+ throw new IllegalArgumentException("Num bits must be between 0 and 32");
+ }
+ ensureCapacity(size + numBits);
+ for (int numBitsLeft = numBits; numBitsLeft > 0; numBitsLeft--) {
+ appendBit(((value >> (numBitsLeft - 1)) & 0x01) == 1);
+ }
+ }
+
+ public void appendBitArray(BitArray other) {
+ int otherSize = other.getSize();
+ ensureCapacity(size + otherSize);
+ for (int i = 0; i < otherSize; i++) {
+ appendBit(other.get(i));
+ }
+ }
+
+ public void xor(BitArray other) {
+ if (bits.length != other.bits.length) {
+ throw new IllegalArgumentException("Sizes don't match");
+ }
+ for (int i = 0; i < bits.length; i++) {
+ // The last byte could be incomplete (i.e. not have 8 bits in
+ // it) but there is no problem since 0 XOR 0 == 0.
+ bits[i] ^= other.bits[i];
+ }
+ }
+
+ /**
+ *
+ * @param bitOffset first bit to start writing
+ * @param array array to write into. Bytes are written most-significant byte first. This is the opposite
+ * of the internal representation, which is exposed by {@link #getBitArray()}
+ * @param offset position in array to start writing
+ * @param numBytes how many bytes to write
+ */
+ public void toBytes(int bitOffset, byte[] array, int offset, int numBytes) {
+ for (int i = 0; i < numBytes; i++) {
+ int theByte = 0;
+ for (int j = 0; j < 8; j++) {
+ if (get(bitOffset)) {
+ theByte |= 1 << (7 - j);
+ }
+ bitOffset++;
+ }
+ array[offset + i] = (byte) theByte;
+ }
+ }
+
+ /**
+ * @return underlying array of ints. The first element holds the first 32 bits, and the least
+ * significant bit is bit 0.
+ */
+ public int[] getBitArray() {
+ return bits;
+ }
+
+ /**
+ * Reverses all bits in the array.
+ */
+ public void reverse() {
+ int[] newBits = new int[bits.length];
+ int size = this.size;
+ for (int i = 0; i < size; i++) {
+ if (get(size - i - 1)) {
+ newBits[i >> 5] |= 1 << (i & 0x1F);
+ }
+ }
+ bits = newBits;
+ }
+
+ private static int[] makeArray(int size) {
+ return new int[(size + 31) >> 5];
+ }
+
+ public String toString() {
+ StringBuffer result = new StringBuffer(size);
+ for (int i = 0; i < size; i++) {
+ if ((i & 0x07) == 0) {
+ result.append(' ');
+ }
+ result.append(get(i) ? 'X' : '.');
+ }
+ return result.toString();
+ }
+
+}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/BitMatrix.java b/libraries/zxing/src/com/google/zxing/common/BitMatrix.java new file mode 100644 index 000000000..8bf75b289 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/BitMatrix.java @@ -0,0 +1,247 @@ +/*
+ * Copyright 2007 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.common;
+
+/**
+ * <p>Represents a 2D matrix of bits. In function arguments below, and throughout the common
+ * module, x is the column position, and y is the row position. The ordering is always x, y.
+ * The origin is at the top-left.</p>
+ *
+ * <p>Internally the bits are represented in a 1-D array of 32-bit ints. However, each row begins
+ * with a new int. This is done intentionally so that we can copy out a row into a BitArray very
+ * efficiently.</p>
+ *
+ * <p>The ordering of bits is row-major. Within each int, the least significant bits are used first,
+ * meaning they represent lower x values. This is compatible with BitArray's implementation.</p>
+ *
+ * @author Sean Owen
+ * @author dswitkin@google.com (Daniel Switkin)
+ */
+public final class BitMatrix {
+ // Just like BitArray, these need to be public so ProGuard can inline them.
+ public final int width;
+ public final int height;
+ public final int rowSize;
+ public final int[] bits;
+
+ // A helper to construct a square matrix.
+ public BitMatrix(int dimension) {
+ this(dimension, dimension);
+ }
+
+ public BitMatrix(int width, int height) {
+ if (width < 1 || height < 1) {
+ throw new IllegalArgumentException("Both dimensions must be greater than 0");
+ }
+ this.width = width;
+ this.height = height;
+ this.rowSize = (width + 31) >> 5;
+ bits = new int[rowSize * height];
+ }
+
+ /**
+ * <p>Gets the requested bit, where true means black.</p>
+ *
+ * @param x The horizontal component (i.e. which column)
+ * @param y The vertical component (i.e. which row)
+ * @return value of given bit in matrix
+ */
+ public boolean get(int x, int y) {
+ int offset = y * rowSize + (x >> 5);
+ return ((bits[offset] >>> (x & 0x1f)) & 1) != 0;
+ }
+
+ /**
+ * <p>Sets the given bit to true.</p>
+ *
+ * @param x The horizontal component (i.e. which column)
+ * @param y The vertical component (i.e. which row)
+ */
+ public void set(int x, int y) {
+ int offset = y * rowSize + (x >> 5);
+ bits[offset] |= 1 << (x & 0x1f);
+ }
+
+ /**
+ * <p>Flips the given bit.</p>
+ *
+ * @param x The horizontal component (i.e. which column)
+ * @param y The vertical component (i.e. which row)
+ */
+ public void flip(int x, int y) {
+ int offset = y * rowSize + (x >> 5);
+ bits[offset] ^= 1 << (x & 0x1f);
+ }
+
+ /**
+ * Clears all bits (sets to false).
+ */
+ public void clear() {
+ int max = bits.length;
+ for (int i = 0; i < max; i++) {
+ bits[i] = 0;
+ }
+ }
+
+ /**
+ * <p>Sets a square region of the bit matrix to true.</p>
+ *
+ * @param left The horizontal position to begin at (inclusive)
+ * @param top The vertical position to begin at (inclusive)
+ * @param width The width of the region
+ * @param height The height of the region
+ */
+ public void setRegion(int left, int top, int width, int height) {
+ if (top < 0 || left < 0) {
+ throw new IllegalArgumentException("Left and top must be nonnegative");
+ }
+ if (height < 1 || width < 1) {
+ throw new IllegalArgumentException("Height and width must be at least 1");
+ }
+ int right = left + width;
+ int bottom = top + height;
+ if (bottom > this.height || right > this.width) {
+ throw new IllegalArgumentException("The region must fit inside the matrix");
+ }
+ for (int y = top; y < bottom; y++) {
+ int offset = y * rowSize;
+ for (int x = left; x < right; x++) {
+ bits[offset + (x >> 5)] |= 1 << (x & 0x1f);
+ }
+ }
+ }
+
+ /**
+ * A fast method to retrieve one row of data from the matrix as a BitArray.
+ *
+ * @param y The row to retrieve
+ * @param row An optional caller-allocated BitArray, will be allocated if null or too small
+ * @return The resulting BitArray - this reference should always be used even when passing
+ * your own row
+ */
+ public BitArray getRow(int y, BitArray row) {
+ if (row == null || row.getSize() < width) {
+ row = new BitArray(width);
+ }
+ int offset = y * rowSize;
+ for (int x = 0; x < rowSize; x++) {
+ row.setBulk(x << 5, bits[offset + x]);
+ }
+ return row;
+ }
+
+ /**
+ * This is useful in detecting a corner of a 'pure' barcode.
+ *
+ * @return {x,y} coordinate of top-left-most 1 bit, or null if it is all white
+ */
+ public int[] getTopLeftOnBit() {
+ int bitsOffset = 0;
+ while (bitsOffset < bits.length && bits[bitsOffset] == 0) {
+ bitsOffset++;
+ }
+ if (bitsOffset == bits.length) {
+ return null;
+ }
+ int y = bitsOffset / rowSize;
+ int x = (bitsOffset % rowSize) << 5;
+
+ int theBits = bits[bitsOffset];
+ int bit = 0;
+ while ((theBits << (31-bit)) == 0) {
+ bit++;
+ }
+ x += bit;
+ return new int[] {x, y};
+ }
+
+ public int[] getBottomRightOnBit() {
+ int bitsOffset = bits.length - 1;
+ while (bitsOffset >= 0 && bits[bitsOffset] == 0) {
+ bitsOffset--;
+ }
+ if (bitsOffset < 0) {
+ return null;
+ }
+
+ int y = bitsOffset / rowSize;
+ int x = (bitsOffset % rowSize) << 5;
+
+ int theBits = bits[bitsOffset];
+ int bit = 31;
+ while ((theBits >>> bit) == 0) {
+ bit--;
+ }
+ x += bit;
+
+ return new int[] {x, y};
+ }
+
+ /**
+ * @return The width of the matrix
+ */
+ public int getWidth() {
+ return width;
+ }
+
+ /**
+ * @return The height of the matrix
+ */
+ public int getHeight() {
+ return height;
+ }
+
+ public boolean equals(Object o) {
+ if (!(o instanceof BitMatrix)) {
+ return false;
+ }
+ BitMatrix other = (BitMatrix) o;
+ if (width != other.width || height != other.height ||
+ rowSize != other.rowSize || bits.length != other.bits.length) {
+ return false;
+ }
+ for (int i = 0; i < bits.length; i++) {
+ if (bits[i] != other.bits[i]) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ public int hashCode() {
+ int hash = width;
+ hash = 31 * hash + width;
+ hash = 31 * hash + height;
+ hash = 31 * hash + rowSize;
+ for (int i = 0; i < bits.length; i++) {
+ hash = 31 * hash + bits[i];
+ }
+ return hash;
+ }
+
+ public String toString() {
+ StringBuffer result = new StringBuffer(height * (width + 1));
+ for (int y = 0; y < height; y++) {
+ for (int x = 0; x < width; x++) {
+ result.append(get(x, y) ? "X " : " ");
+ }
+ result.append('\n');
+ }
+ return result.toString();
+ }
+
+}
diff --git a/libraries/zxing/src/com/google/zxing/common/BitSource.java b/libraries/zxing/src/com/google/zxing/common/BitSource.java new file mode 100644 index 000000000..a61ac5105 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/BitSource.java @@ -0,0 +1,97 @@ +/*
+ * Copyright 2007 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.common;
+
+/**
+ * <p>This provides an easy abstraction to read bits at a time from a sequence of bytes, where the
+ * number of bits read is not often a multiple of 8.</p>
+ *
+ * <p>This class is thread-safe but not reentrant. Unless the caller modifies the bytes array
+ * it passed in, in which case all bets are off.</p>
+ *
+ * @author Sean Owen
+ */
+public final class BitSource {
+
+ private final byte[] bytes;
+ private int byteOffset;
+ private int bitOffset;
+
+ /**
+ * @param bytes bytes from which this will read bits. Bits will be read from the first byte first.
+ * Bits are read within a byte from most-significant to least-significant bit.
+ */
+ public BitSource(byte[] bytes) {
+ this.bytes = bytes;
+ }
+
+ /**
+ * @param numBits number of bits to read
+ * @return int representing the bits read. The bits will appear as the least-significant
+ * bits of the int
+ * @throws IllegalArgumentException if numBits isn't in [1,32]
+ */
+ public int readBits(int numBits) {
+ if (numBits < 1 || numBits > 32) {
+ throw new IllegalArgumentException();
+ }
+
+ int result = 0;
+
+ // First, read remainder from current byte
+ if (bitOffset > 0) {
+ int bitsLeft = 8 - bitOffset;
+ int toRead = numBits < bitsLeft ? numBits : bitsLeft;
+ int bitsToNotRead = bitsLeft - toRead;
+ int mask = (0xFF >> (8 - toRead)) << bitsToNotRead;
+ result = (bytes[byteOffset] & mask) >> bitsToNotRead;
+ numBits -= toRead;
+ bitOffset += toRead;
+ if (bitOffset == 8) {
+ bitOffset = 0;
+ byteOffset++;
+ }
+ }
+
+ // Next read whole bytes
+ if (numBits > 0) {
+ while (numBits >= 8) {
+ result = (result << 8) | (bytes[byteOffset] & 0xFF);
+ byteOffset++;
+ numBits -= 8;
+ }
+
+ // Finally read a partial byte
+ if (numBits > 0) {
+ int bitsToNotRead = 8 - numBits;
+ int mask = (0xFF >> bitsToNotRead) << bitsToNotRead;
+ result = (result << numBits) | ((bytes[byteOffset] & mask) >> bitsToNotRead);
+ bitOffset += numBits;
+ }
+ }
+
+ return result;
+ }
+
+ /**
+ * @return number of bits that can be read successfully
+ */
+ public int available() {
+ return 8 * (bytes.length - byteOffset) - bitOffset;
+ }
+
+}
diff --git a/libraries/zxing/src/com/google/zxing/common/CharacterSetECI.java b/libraries/zxing/src/com/google/zxing/common/CharacterSetECI.java new file mode 100644 index 000000000..42b7fa9f6 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/CharacterSetECI.java @@ -0,0 +1,110 @@ +/* + * Copyright 2008 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import java.util.Hashtable; + +/** + * Encapsulates a Character Set ECI, according to "Extended Channel Interpretations" 5.3.1.1 + * of ISO 18004. + * + * @author Sean Owen + */ +public final class CharacterSetECI extends ECI { + + private static Hashtable VALUE_TO_ECI; + private static Hashtable NAME_TO_ECI; + + private static void initialize() { + VALUE_TO_ECI = new Hashtable(29); + NAME_TO_ECI = new Hashtable(29); + // TODO figure out if these values are even right! + addCharacterSet(0, "Cp437"); + addCharacterSet(1, new String[] {"ISO8859_1", "ISO-8859-1"}); + addCharacterSet(2, "Cp437"); + addCharacterSet(3, new String[] {"ISO8859_1", "ISO-8859-1"}); + addCharacterSet(4, "ISO8859_2"); + addCharacterSet(5, "ISO8859_3"); + addCharacterSet(6, "ISO8859_4"); + addCharacterSet(7, "ISO8859_5"); + addCharacterSet(8, "ISO8859_6"); + addCharacterSet(9, "ISO8859_7"); + addCharacterSet(10, "ISO8859_8"); + addCharacterSet(11, "ISO8859_9"); + addCharacterSet(12, "ISO8859_10"); + addCharacterSet(13, "ISO8859_11"); + addCharacterSet(15, "ISO8859_13"); + addCharacterSet(16, "ISO8859_14"); + addCharacterSet(17, "ISO8859_15"); + addCharacterSet(18, "ISO8859_16"); + addCharacterSet(20, new String[] {"SJIS", "Shift_JIS"}); + } + + private final String encodingName; + + private CharacterSetECI(int value, String encodingName) { + super(value); + this.encodingName = encodingName; + } + + public String getEncodingName() { + return encodingName; + } + + private static void addCharacterSet(int value, String encodingName) { + CharacterSetECI eci = new CharacterSetECI(value, encodingName); + VALUE_TO_ECI.put(new Integer(value), eci); // can't use valueOf + NAME_TO_ECI.put(encodingName, eci); + } + + private static void addCharacterSet(int value, String[] encodingNames) { + CharacterSetECI eci = new CharacterSetECI(value, encodingNames[0]); + VALUE_TO_ECI.put(new Integer(value), eci); // can't use valueOf + for (int i = 0; i < encodingNames.length; i++) { + NAME_TO_ECI.put(encodingNames[i], eci); + } + } + + /** + * @param value character set ECI value + * @return CharacterSetECI representing ECI of given value, or null if it is legal but + * unsupported + * @throws IllegalArgumentException if ECI value is invalid + */ + public static CharacterSetECI getCharacterSetECIByValue(int value) { + if (VALUE_TO_ECI == null) { + initialize(); + } + if (value < 0 || value >= 900) { + throw new IllegalArgumentException("Bad ECI value: " + value); + } + return (CharacterSetECI) VALUE_TO_ECI.get(new Integer(value)); + } + + /** + * @param name character set ECI encoding name + * @return CharacterSetECI representing ECI for character encoding, or null if it is legal + * but unsupported + */ + public static CharacterSetECI getCharacterSetECIByName(String name) { + if (NAME_TO_ECI == null) { + initialize(); + } + return (CharacterSetECI) NAME_TO_ECI.get(name); + } + +}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/Collections.java b/libraries/zxing/src/com/google/zxing/common/Collections.java new file mode 100644 index 000000000..319ebfe6d --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/Collections.java @@ -0,0 +1,53 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import java.util.Vector; + +/** + * <p>This is basically a substitute for <code>java.util.Collections</code>, which is not + * present in MIDP 2.0 / CLDC 1.1.</p> + * + * @author Sean Owen + */ +public final class Collections { + + private Collections() { + } + + /** + * Sorts its argument (destructively) using insert sort; in the context of this package + * insertion sort is simple and efficient given its relatively small inputs. + * + * @param vector vector to sort + * @param comparator comparator to define sort ordering + */ + public static void insertionSort(Vector vector, Comparator comparator) { + int max = vector.size(); + for (int i = 1; i < max; i++) { + Object value = vector.elementAt(i); + int j = i - 1; + Object valueB; + while (j >= 0 && comparator.compare((valueB = vector.elementAt(j)), value) > 0) { + vector.setElementAt(valueB, j + 1); + j--; + } + vector.setElementAt(value, j + 1); + } + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/Comparator.java b/libraries/zxing/src/com/google/zxing/common/Comparator.java new file mode 100644 index 000000000..e1be15e31 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/Comparator.java @@ -0,0 +1,27 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +/** + * This is merely a clone of <code>Comparator</code> since it is not available in + * CLDC 1.1 / MIDP 2.0. + */ +public interface Comparator { + + int compare(Object o1, Object o2); + +}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/DecoderResult.java b/libraries/zxing/src/com/google/zxing/common/DecoderResult.java new file mode 100644 index 000000000..7e0855333 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/DecoderResult.java @@ -0,0 +1,61 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import java.util.Vector; + +/** + * <p>Encapsulates the result of decoding a matrix of bits. This typically + * applies to 2D barcode formats. For now it contains the raw bytes obtained, + * as well as a String interpretation of those bytes, if applicable.</p> + * + * @author Sean Owen + */ +public final class DecoderResult { + + private final byte[] rawBytes; + private final String text; + private final Vector byteSegments; + private final String ecLevel; + + public DecoderResult(byte[] rawBytes, String text, Vector byteSegments, String ecLevel) { + if (rawBytes == null && text == null) { + throw new IllegalArgumentException(); + } + this.rawBytes = rawBytes; + this.text = text; + this.byteSegments = byteSegments; + this.ecLevel = ecLevel; + } + + public byte[] getRawBytes() { + return rawBytes; + } + + public String getText() { + return text; + } + + public Vector getByteSegments() { + return byteSegments; + } + + public String getECLevel() { + return ecLevel; + } + +}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/DefaultGridSampler.java b/libraries/zxing/src/com/google/zxing/common/DefaultGridSampler.java new file mode 100644 index 000000000..74c9e7c6b --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/DefaultGridSampler.java @@ -0,0 +1,86 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import com.google.zxing.NotFoundException; + +/** + * @author Sean Owen + */ +public final class DefaultGridSampler extends GridSampler { + + public BitMatrix sampleGrid(BitMatrix image, + int dimensionX, + int dimensionY, + float p1ToX, float p1ToY, + float p2ToX, float p2ToY, + float p3ToX, float p3ToY, + float p4ToX, float p4ToY, + float p1FromX, float p1FromY, + float p2FromX, float p2FromY, + float p3FromX, float p3FromY, + float p4FromX, float p4FromY) throws NotFoundException { + + PerspectiveTransform transform = PerspectiveTransform.quadrilateralToQuadrilateral( + p1ToX, p1ToY, p2ToX, p2ToY, p3ToX, p3ToY, p4ToX, p4ToY, + p1FromX, p1FromY, p2FromX, p2FromY, p3FromX, p3FromY, p4FromX, p4FromY); + + return sampleGrid(image, dimensionX, dimensionY, transform); + } + + public BitMatrix sampleGrid(BitMatrix image, + int dimensionX, + int dimensionY, + PerspectiveTransform transform) throws NotFoundException { + if (dimensionX <= 0 || dimensionY <= 0) { + throw NotFoundException.getNotFoundInstance(); + } + BitMatrix bits = new BitMatrix(dimensionX, dimensionY); + float[] points = new float[dimensionX << 1]; + for (int y = 0; y < dimensionY; y++) { + int max = points.length; + float iValue = (float) y + 0.5f; + for (int x = 0; x < max; x += 2) { + points[x] = (float) (x >> 1) + 0.5f; + points[x + 1] = iValue; + } + transform.transformPoints(points); + // Quick check to see if points transformed to something inside the image; + // sufficient to check the endpoints + checkAndNudgePoints(image, points); + try { + for (int x = 0; x < max; x += 2) { + if (image.get((int) points[x], (int) points[x + 1])) { + // Black(-ish) pixel + bits.set(x >> 1, y); + } + } + } catch (ArrayIndexOutOfBoundsException aioobe) { + // This feels wrong, but, sometimes if the finder patterns are misidentified, the resulting + // transform gets "twisted" such that it maps a straight line of points to a set of points + // whose endpoints are in bounds, but others are not. There is probably some mathematical + // way to detect this about the transformation that I don't know yet. + // This results in an ugly runtime exception despite our clever checks above -- can't have + // that. We could check each point's coordinates but that feels duplicative. We settle for + // catching and wrapping ArrayIndexOutOfBoundsException. + throw NotFoundException.getNotFoundInstance(); + } + } + return bits; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/DetectorResult.java b/libraries/zxing/src/com/google/zxing/common/DetectorResult.java new file mode 100644 index 000000000..ea4794d17 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/DetectorResult.java @@ -0,0 +1,46 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import com.google.zxing.ResultPoint; + +/** + * <p>Encapsulates the result of detecting a barcode in an image. This includes the raw + * matrix of black/white pixels corresponding to the barcode, and possibly points of interest + * in the image, like the location of finder patterns or corners of the barcode in the image.</p> + * + * @author Sean Owen + */ +public class DetectorResult { + + private final BitMatrix bits; + private final ResultPoint[] points; + + public DetectorResult(BitMatrix bits, ResultPoint[] points) { + this.bits = bits; + this.points = points; + } + + public BitMatrix getBits() { + return bits; + } + + public ResultPoint[] getPoints() { + return points; + } + +}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/ECI.java b/libraries/zxing/src/com/google/zxing/common/ECI.java new file mode 100644 index 000000000..444c779c2 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/ECI.java @@ -0,0 +1,52 @@ +/* + * Copyright 2008 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +/** + * Superclass of classes encapsulating types ECIs, according to "Extended Channel Interpretations" + * 5.3 of ISO 18004. + * + * @author Sean Owen + */ +public abstract class ECI { + + private final int value; + + ECI(int value) { + this.value = value; + } + + public int getValue() { + return value; + } + + /** + * @param value ECI value + * @return ECI representing ECI of given value, or null if it is legal but unsupported + * @throws IllegalArgumentException if ECI value is invalid + */ + public static ECI getECIByValue(int value) { + if (value < 0 || value > 999999) { + throw new IllegalArgumentException("Bad ECI value: " + value); + } + if (value < 900) { // Character set ECIs use 000000 - 000899 + return CharacterSetECI.getCharacterSetECIByValue(value); + } + return null; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/GlobalHistogramBinarizer.java b/libraries/zxing/src/com/google/zxing/common/GlobalHistogramBinarizer.java new file mode 100644 index 000000000..4fa2a887b --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/GlobalHistogramBinarizer.java @@ -0,0 +1,194 @@ +/* + * Copyright 2009 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import com.google.zxing.Binarizer; +import com.google.zxing.LuminanceSource; +import com.google.zxing.NotFoundException; + +/** + * This Binarizer implementation uses the old ZXing global histogram approach. It is suitable + * for low-end mobile devices which don't have enough CPU or memory to use a local thresholding + * algorithm. However, because it picks a global black point, it cannot handle difficult shadows + * and gradients. + * + * Faster mobile devices and all desktop applications should probably use HybridBinarizer instead. + * + * @author dswitkin@google.com (Daniel Switkin) + * @author Sean Owen + */ +public class GlobalHistogramBinarizer extends Binarizer { + + private static final int LUMINANCE_BITS = 5; + private static final int LUMINANCE_SHIFT = 8 - LUMINANCE_BITS; + private static final int LUMINANCE_BUCKETS = 1 << LUMINANCE_BITS; + + private byte[] luminances = null; + private int[] buckets = null; + + public GlobalHistogramBinarizer(LuminanceSource source) { + super(source); + } + + // Applies simple sharpening to the row data to improve performance of the 1D Readers. + public BitArray getBlackRow(int y, BitArray row) throws NotFoundException { + LuminanceSource source = getLuminanceSource(); + int width = source.getWidth(); + if (row == null || row.getSize() < width) { + row = new BitArray(width); + } else { + row.clear(); + } + + initArrays(width); + byte[] localLuminances = source.getRow(y, luminances); + int[] localBuckets = buckets; + for (int x = 0; x < width; x++) { + int pixel = localLuminances[x] & 0xff; + localBuckets[pixel >> LUMINANCE_SHIFT]++; + } + int blackPoint = estimateBlackPoint(localBuckets); + + int left = localLuminances[0] & 0xff; + int center = localLuminances[1] & 0xff; + for (int x = 1; x < width - 1; x++) { + int right = localLuminances[x + 1] & 0xff; + // A simple -1 4 -1 box filter with a weight of 2. + int luminance = ((center << 2) - left - right) >> 1; + if (luminance < blackPoint) { + row.set(x); + } + left = center; + center = right; + } + return row; + } + + // Does not sharpen the data, as this call is intended to only be used by 2D Readers. + public BitMatrix getBlackMatrix() throws NotFoundException { + LuminanceSource source = getLuminanceSource(); + int width = source.getWidth(); + int height = source.getHeight(); + BitMatrix matrix = new BitMatrix(width, height); + + // Quickly calculates the histogram by sampling four rows from the image. This proved to be + // more robust on the blackbox tests than sampling a diagonal as we used to do. + initArrays(width); + int[] localBuckets = buckets; + for (int y = 1; y < 5; y++) { + int row = height * y / 5; + byte[] localLuminances = source.getRow(row, luminances); + int right = (width << 2) / 5; + for (int x = width / 5; x < right; x++) { + int pixel = localLuminances[x] & 0xff; + localBuckets[pixel >> LUMINANCE_SHIFT]++; + } + } + int blackPoint = estimateBlackPoint(localBuckets); + + // We delay reading the entire image luminance until the black point estimation succeeds. + // Although we end up reading four rows twice, it is consistent with our motto of + // "fail quickly" which is necessary for continuous scanning. + byte[] localLuminances = source.getMatrix(); + for (int y = 0; y < height; y++) { + int offset = y * width; + for (int x = 0; x< width; x++) { + int pixel = localLuminances[offset + x] & 0xff; + if (pixel < blackPoint) { + matrix.set(x, y); + } + } + } + + return matrix; + } + + public Binarizer createBinarizer(LuminanceSource source) { + return new GlobalHistogramBinarizer(source); + } + + private void initArrays(int luminanceSize) { + if (luminances == null || luminances.length < luminanceSize) { + luminances = new byte[luminanceSize]; + } + if (buckets == null) { + buckets = new int[LUMINANCE_BUCKETS]; + } else { + for (int x = 0; x < LUMINANCE_BUCKETS; x++) { + buckets[x] = 0; + } + } + } + + private static int estimateBlackPoint(int[] buckets) throws NotFoundException { + // Find the tallest peak in the histogram. + int numBuckets = buckets.length; + int maxBucketCount = 0; + int firstPeak = 0; + int firstPeakSize = 0; + for (int x = 0; x < numBuckets; x++) { + if (buckets[x] > firstPeakSize) { + firstPeak = x; + firstPeakSize = buckets[x]; + } + if (buckets[x] > maxBucketCount) { + maxBucketCount = buckets[x]; + } + } + + // Find the second-tallest peak which is somewhat far from the tallest peak. + int secondPeak = 0; + int secondPeakScore = 0; + for (int x = 0; x < numBuckets; x++) { + int distanceToBiggest = x - firstPeak; + // Encourage more distant second peaks by multiplying by square of distance. + int score = buckets[x] * distanceToBiggest * distanceToBiggest; + if (score > secondPeakScore) { + secondPeak = x; + secondPeakScore = score; + } + } + + // Make sure firstPeak corresponds to the black peak. + if (firstPeak > secondPeak) { + int temp = firstPeak; + firstPeak = secondPeak; + secondPeak = temp; + } + + // If there is too little contrast in the image to pick a meaningful black point, throw rather + // than waste time trying to decode the image, and risk false positives. + if (secondPeak - firstPeak <= numBuckets >> 4) { + throw NotFoundException.getNotFoundInstance(); + } + + // Find a valley between them that is low and closer to the white peak. + int bestValley = secondPeak - 1; + int bestValleyScore = -1; + for (int x = secondPeak - 1; x > firstPeak; x--) { + int fromFirst = x - firstPeak; + int score = fromFirst * fromFirst * (secondPeak - x) * (maxBucketCount - buckets[x]); + if (score > bestValleyScore) { + bestValley = x; + bestValleyScore = score; + } + } + + return bestValley << LUMINANCE_SHIFT; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/GridSampler.java b/libraries/zxing/src/com/google/zxing/common/GridSampler.java new file mode 100644 index 000000000..7f26c264e --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/GridSampler.java @@ -0,0 +1,156 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import com.google.zxing.NotFoundException; + +/** + * Implementations of this class can, given locations of finder patterns for a QR code in an + * image, sample the right points in the image to reconstruct the QR code, accounting for + * perspective distortion. It is abstracted since it is relatively expensive and should be allowed + * to take advantage of platform-specific optimized implementations, like Sun's Java Advanced + * Imaging library, but which may not be available in other environments such as J2ME, and vice + * versa. + * + * The implementation used can be controlled by calling {@link #setGridSampler(GridSampler)} + * with an instance of a class which implements this interface. + * + * @author Sean Owen + */ +public abstract class GridSampler { + + private static GridSampler gridSampler = new DefaultGridSampler(); + + /** + * Sets the implementation of GridSampler used by the library. One global + * instance is stored, which may sound problematic. But, the implementation provided + * ought to be appropriate for the entire platform, and all uses of this library + * in the whole lifetime of the JVM. For instance, an Android activity can swap in + * an implementation that takes advantage of native platform libraries. + * + * @param newGridSampler The platform-specific object to install. + */ + public static void setGridSampler(GridSampler newGridSampler) { + if (newGridSampler == null) { + throw new IllegalArgumentException(); + } + gridSampler = newGridSampler; + } + + /** + * @return the current implementation of GridSampler + */ + public static GridSampler getInstance() { + return gridSampler; + } + + /** + * Samples an image for a rectangular matrix of bits of the given dimension. + * @param image image to sample + * @param dimensionX width of {@link BitMatrix} to sample from image + * @param dimensionY height of {@link BitMatrix} to sample from image + * @return {@link BitMatrix} representing a grid of points sampled from the image within a region + * defined by the "from" parameters + * @throws NotFoundException if image can't be sampled, for example, if the transformation defined + * by the given points is invalid or results in sampling outside the image boundaries + */ + public abstract BitMatrix sampleGrid(BitMatrix image, + int dimensionX, + int dimensionY, + float p1ToX, float p1ToY, + float p2ToX, float p2ToY, + float p3ToX, float p3ToY, + float p4ToX, float p4ToY, + float p1FromX, float p1FromY, + float p2FromX, float p2FromY, + float p3FromX, float p3FromY, + float p4FromX, float p4FromY) throws NotFoundException; + + public abstract BitMatrix sampleGrid(BitMatrix image, + int dimensionX, + int dimensionY, + PerspectiveTransform transform) throws NotFoundException; + + /** + * <p>Checks a set of points that have been transformed to sample points on an image against + * the image's dimensions to see if the point are even within the image.</p> + * + * <p>This method will actually "nudge" the endpoints back onto the image if they are found to be + * barely (less than 1 pixel) off the image. This accounts for imperfect detection of finder + * patterns in an image where the QR Code runs all the way to the image border.</p> + * + * <p>For efficiency, the method will check points from either end of the line until one is found + * to be within the image. Because the set of points are assumed to be linear, this is valid.</p> + * + * @param image image into which the points should map + * @param points actual points in x1,y1,...,xn,yn form + * @throws NotFoundException if an endpoint is lies outside the image boundaries + */ + protected static void checkAndNudgePoints(BitMatrix image, float[] points) throws NotFoundException { + int width = image.getWidth(); + int height = image.getHeight(); + // Check and nudge points from start until we see some that are OK: + boolean nudged = true; + for (int offset = 0; offset < points.length && nudged; offset += 2) { + int x = (int) points[offset]; + int y = (int) points[offset + 1]; + if (x < -1 || x > width || y < -1 || y > height) { + throw NotFoundException.getNotFoundInstance(); + } + nudged = false; + if (x == -1) { + points[offset] = 0.0f; + nudged = true; + } else if (x == width) { + points[offset] = width - 1; + nudged = true; + } + if (y == -1) { + points[offset + 1] = 0.0f; + nudged = true; + } else if (y == height) { + points[offset + 1] = height - 1; + nudged = true; + } + } + // Check and nudge points from end: + nudged = true; + for (int offset = points.length - 2; offset >= 0 && nudged; offset -= 2) { + int x = (int) points[offset]; + int y = (int) points[offset + 1]; + if (x < -1 || x > width || y < -1 || y > height) { + throw NotFoundException.getNotFoundInstance(); + } + nudged = false; + if (x == -1) { + points[offset] = 0.0f; + nudged = true; + } else if (x == width) { + points[offset] = width - 1; + nudged = true; + } + if (y == -1) { + points[offset + 1] = 0.0f; + nudged = true; + } else if (y == height) { + points[offset + 1] = height - 1; + nudged = true; + } + } + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/HybridBinarizer.java b/libraries/zxing/src/com/google/zxing/common/HybridBinarizer.java new file mode 100644 index 000000000..b482c1a22 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/HybridBinarizer.java @@ -0,0 +1,185 @@ +/* + * Copyright 2009 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import com.google.zxing.Binarizer; +import com.google.zxing.LuminanceSource; +import com.google.zxing.NotFoundException; + +/** + * This class implements a local thresholding algorithm, which while slower than the + * GlobalHistogramBinarizer, is fairly efficient for what it does. It is designed for + * high frequency images of barcodes with black data on white backgrounds. For this application, + * it does a much better job than a global blackpoint with severe shadows and gradients. + * However it tends to produce artifacts on lower frequency images and is therefore not + * a good general purpose binarizer for uses outside ZXing. + * + * This class extends GlobalHistogramBinarizer, using the older histogram approach for 1D readers, + * and the newer local approach for 2D readers. 1D decoding using a per-row histogram is already + * inherently local, and only fails for horizontal gradients. We can revisit that problem later, + * but for now it was not a win to use local blocks for 1D. + * + * This Binarizer is the default for the unit tests and the recommended class for library users. + * + * @author dswitkin@google.com (Daniel Switkin) + */ +public final class HybridBinarizer extends GlobalHistogramBinarizer { + + // This class uses 5x5 blocks to compute local luminance, where each block is 8x8 pixels. + // So this is the smallest dimension in each axis we can accept. + private static final int MINIMUM_DIMENSION = 40; + + private BitMatrix matrix = null; + + public HybridBinarizer(LuminanceSource source) { + super(source); + } + + public BitMatrix getBlackMatrix() throws NotFoundException { + binarizeEntireImage(); + return matrix; + } + + public Binarizer createBinarizer(LuminanceSource source) { + return new HybridBinarizer(source); + } + + // Calculates the final BitMatrix once for all requests. This could be called once from the + // constructor instead, but there are some advantages to doing it lazily, such as making + // profiling easier, and not doing heavy lifting when callers don't expect it. + private void binarizeEntireImage() throws NotFoundException { + if (matrix == null) { + LuminanceSource source = getLuminanceSource(); + if (source.getWidth() >= MINIMUM_DIMENSION && source.getHeight() >= MINIMUM_DIMENSION) { + byte[] luminances = source.getMatrix(); + int width = source.getWidth(); + int height = source.getHeight(); + int subWidth = width >> 3; + if ((width & 0x07) != 0) { + subWidth++; + } + int subHeight = height >> 3; + if ((height & 0x07) != 0) { + subHeight++; + } + int[][] blackPoints = calculateBlackPoints(luminances, subWidth, subHeight, width, height); + + matrix = new BitMatrix(width, height); + calculateThresholdForBlock(luminances, subWidth, subHeight, width, height, blackPoints, matrix); + } else { + // If the image is too small, fall back to the global histogram approach. + matrix = super.getBlackMatrix(); + } + } + } + + // For each 8x8 block in the image, calculate the average black point using a 5x5 grid + // of the blocks around it. Also handles the corner cases (fractional blocks are computed based + // on the last 8 pixels in the row/column which are also used in the previous block). + private static void calculateThresholdForBlock(byte[] luminances, int subWidth, int subHeight, + int width, int height, int[][] blackPoints, BitMatrix matrix) { + for (int y = 0; y < subHeight; y++) { + int yoffset = y << 3; + if ((yoffset + 8) >= height) { + yoffset = height - 8; + } + for (int x = 0; x < subWidth; x++) { + int xoffset = x << 3; + if ((xoffset + 8) >= width) { + xoffset = width - 8; + } + int left = x > 1 ? x : 2; + left = left < subWidth - 2 ? left : subWidth - 3; + int top = y > 1 ? y : 2; + top = top < subHeight - 2 ? top : subHeight - 3; + int sum = 0; + for (int z = -2; z <= 2; z++) { + int[] blackRow = blackPoints[top + z]; + sum += blackRow[left - 2]; + sum += blackRow[left - 1]; + sum += blackRow[left]; + sum += blackRow[left + 1]; + sum += blackRow[left + 2]; + } + int average = sum / 25; + threshold8x8Block(luminances, xoffset, yoffset, average, width, matrix); + } + } + } + + // Applies a single threshold to an 8x8 block of pixels. + private static void threshold8x8Block(byte[] luminances, int xoffset, int yoffset, int threshold, + int stride, BitMatrix matrix) { + for (int y = 0; y < 8; y++) { + int offset = (yoffset + y) * stride + xoffset; + for (int x = 0; x < 8; x++) { + int pixel = luminances[offset + x] & 0xff; + if (pixel < threshold) { + matrix.set(xoffset + x, yoffset + y); + } + } + } + } + + // Calculates a single black point for each 8x8 block of pixels and saves it away. + private static int[][] calculateBlackPoints(byte[] luminances, int subWidth, int subHeight, + int width, int height) { + int[][] blackPoints = new int[subHeight][subWidth]; + for (int y = 0; y < subHeight; y++) { + int yoffset = y << 3; + if ((yoffset + 8) >= height) { + yoffset = height - 8; + } + for (int x = 0; x < subWidth; x++) { + int xoffset = x << 3; + if ((xoffset + 8) >= width) { + xoffset = width - 8; + } + int sum = 0; + int min = 255; + int max = 0; + for (int yy = 0; yy < 8; yy++) { + int offset = (yoffset + yy) * width + xoffset; + for (int xx = 0; xx < 8; xx++) { + int pixel = luminances[offset + xx] & 0xff; + sum += pixel; + if (pixel < min) { + min = pixel; + } + if (pixel > max) { + max = pixel; + } + } + } + + // If the contrast is inadequate, use half the minimum, so that this block will be + // treated as part of the white background, but won't drag down neighboring blocks + // too much. + int average; + if (max - min > 24) { + average = sum >> 6; + } else { + // When min == max == 0, let average be 1 so all is black + average = max == 0 ? 1 : min >> 1; + } + blackPoints[y][x] = average; + } + } + return blackPoints; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/PerspectiveTransform.java b/libraries/zxing/src/com/google/zxing/common/PerspectiveTransform.java new file mode 100644 index 000000000..9e65baff1 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/PerspectiveTransform.java @@ -0,0 +1,148 @@ +/*
+ * Copyright 2007 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.common;
+
+/**
+ * <p>This class implements a perspective transform in two dimensions. Given four source and four
+ * destination points, it will compute the transformation implied between them. The code is based
+ * directly upon section 3.4.2 of George Wolberg's "Digital Image Warping"; see pages 54-56.</p>
+ *
+ * @author Sean Owen
+ */
+public final class PerspectiveTransform {
+
+ private final float a11, a12, a13, a21, a22, a23, a31, a32, a33;
+
+ private PerspectiveTransform(float a11, float a21, float a31,
+ float a12, float a22, float a32,
+ float a13, float a23, float a33) {
+ this.a11 = a11;
+ this.a12 = a12;
+ this.a13 = a13;
+ this.a21 = a21;
+ this.a22 = a22;
+ this.a23 = a23;
+ this.a31 = a31;
+ this.a32 = a32;
+ this.a33 = a33;
+ }
+
+ public static PerspectiveTransform quadrilateralToQuadrilateral(float x0, float y0,
+ float x1, float y1,
+ float x2, float y2,
+ float x3, float y3,
+ float x0p, float y0p,
+ float x1p, float y1p,
+ float x2p, float y2p,
+ float x3p, float y3p) {
+
+ PerspectiveTransform qToS = quadrilateralToSquare(x0, y0, x1, y1, x2, y2, x3, y3);
+ PerspectiveTransform sToQ = squareToQuadrilateral(x0p, y0p, x1p, y1p, x2p, y2p, x3p, y3p);
+ return sToQ.times(qToS);
+ }
+
+ public void transformPoints(float[] points) {
+ int max = points.length;
+ float a11 = this.a11;
+ float a12 = this.a12;
+ float a13 = this.a13;
+ float a21 = this.a21;
+ float a22 = this.a22;
+ float a23 = this.a23;
+ float a31 = this.a31;
+ float a32 = this.a32;
+ float a33 = this.a33;
+ for (int i = 0; i < max; i += 2) {
+ float x = points[i];
+ float y = points[i + 1];
+ float denominator = a13 * x + a23 * y + a33;
+ points[i] = (a11 * x + a21 * y + a31) / denominator;
+ points[i + 1] = (a12 * x + a22 * y + a32) / denominator;
+ }
+ }
+
+ /** Convenience method, not optimized for performance. */
+ public void transformPoints(float[] xValues, float[] yValues) {
+ int n = xValues.length;
+ for (int i = 0; i < n; i ++) {
+ float x = xValues[i];
+ float y = yValues[i];
+ float denominator = a13 * x + a23 * y + a33;
+ xValues[i] = (a11 * x + a21 * y + a31) / denominator;
+ yValues[i] = (a12 * x + a22 * y + a32) / denominator;
+ }
+ }
+
+ public static PerspectiveTransform squareToQuadrilateral(float x0, float y0,
+ float x1, float y1,
+ float x2, float y2,
+ float x3, float y3) {
+ float dy2 = y3 - y2;
+ float dy3 = y0 - y1 + y2 - y3;
+ if (dy2 == 0.0f && dy3 == 0.0f) {
+ return new PerspectiveTransform(x1 - x0, x2 - x1, x0,
+ y1 - y0, y2 - y1, y0,
+ 0.0f, 0.0f, 1.0f);
+ } else {
+ float dx1 = x1 - x2;
+ float dx2 = x3 - x2;
+ float dx3 = x0 - x1 + x2 - x3;
+ float dy1 = y1 - y2;
+ float denominator = dx1 * dy2 - dx2 * dy1;
+ float a13 = (dx3 * dy2 - dx2 * dy3) / denominator;
+ float a23 = (dx1 * dy3 - dx3 * dy1) / denominator;
+ return new PerspectiveTransform(x1 - x0 + a13 * x1, x3 - x0 + a23 * x3, x0,
+ y1 - y0 + a13 * y1, y3 - y0 + a23 * y3, y0,
+ a13, a23, 1.0f);
+ }
+ }
+
+ public static PerspectiveTransform quadrilateralToSquare(float x0, float y0,
+ float x1, float y1,
+ float x2, float y2,
+ float x3, float y3) {
+ // Here, the adjoint serves as the inverse:
+ return squareToQuadrilateral(x0, y0, x1, y1, x2, y2, x3, y3).buildAdjoint();
+ }
+
+ PerspectiveTransform buildAdjoint() {
+ // Adjoint is the transpose of the cofactor matrix:
+ return new PerspectiveTransform(a22 * a33 - a23 * a32,
+ a23 * a31 - a21 * a33,
+ a21 * a32 - a22 * a31,
+ a13 * a32 - a12 * a33,
+ a11 * a33 - a13 * a31,
+ a12 * a31 - a11 * a32,
+ a12 * a23 - a13 * a22,
+ a13 * a21 - a11 * a23,
+ a11 * a22 - a12 * a21);
+ }
+
+ PerspectiveTransform times(PerspectiveTransform other) {
+ return new PerspectiveTransform(a11 * other.a11 + a21 * other.a12 + a31 * other.a13,
+ a11 * other.a21 + a21 * other.a22 + a31 * other.a23,
+ a11 * other.a31 + a21 * other.a32 + a31 * other.a33,
+ a12 * other.a11 + a22 * other.a12 + a32 * other.a13,
+ a12 * other.a21 + a22 * other.a22 + a32 * other.a23,
+ a12 * other.a31 + a22 * other.a32 + a32 * other.a33,
+ a13 * other.a11 + a23 * other.a12 + a33 * other.a13,
+ a13 * other.a21 + a23 * other.a22 + a33 * other.a23,
+ a13 * other.a31 + a23 * other.a32 + a33 * other.a33);
+
+ }
+
+}
diff --git a/libraries/zxing/src/com/google/zxing/common/StringUtils.java b/libraries/zxing/src/com/google/zxing/common/StringUtils.java new file mode 100644 index 000000000..97999f997 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/StringUtils.java @@ -0,0 +1,192 @@ +/* + * Copyright (C) 2010 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common; + +import java.util.Hashtable; + +import com.google.zxing.DecodeHintType; + +/** + * Common string-related functions. + * + * @author Sean Owen + */ +public final class StringUtils { + + private static final String PLATFORM_DEFAULT_ENCODING = + System.getProperty("file.encoding"); + public static final String SHIFT_JIS = "SJIS"; + public static final String GB2312 = "GB2312"; + private static final String EUC_JP = "EUC_JP"; + private static final String UTF8 = "UTF8"; + private static final String ISO88591 = "ISO8859_1"; + private static final boolean ASSUME_SHIFT_JIS = + SHIFT_JIS.equalsIgnoreCase(PLATFORM_DEFAULT_ENCODING) || + EUC_JP.equalsIgnoreCase(PLATFORM_DEFAULT_ENCODING); + + private StringUtils() {} + + /** + * @param bytes bytes encoding a string, whose encoding should be guessed + * @param hints decode hints if applicable + * @return name of guessed encoding; at the moment will only guess one of: + * {@link #SHIFT_JIS}, {@link #UTF8}, {@link #ISO88591}, or the platform + * default encoding if none of these can possibly be correct + */ + public static String guessEncoding(byte[] bytes, Hashtable hints) { + if (hints != null) { + String characterSet = (String) hints.get(DecodeHintType.CHARACTER_SET); + if (characterSet != null) { + return characterSet; + } + } + // Does it start with the UTF-8 byte order mark? then guess it's UTF-8 + if (bytes.length > 3 && + bytes[0] == (byte) 0xEF && + bytes[1] == (byte) 0xBB && + bytes[2] == (byte) 0xBF) { + return UTF8; + } + // For now, merely tries to distinguish ISO-8859-1, UTF-8 and Shift_JIS, + // which should be by far the most common encodings. ISO-8859-1 + // should not have bytes in the 0x80 - 0x9F range, while Shift_JIS + // uses this as a first byte of a two-byte character. If we see this + // followed by a valid second byte in Shift_JIS, assume it is Shift_JIS. + // If we see something else in that second byte, we'll make the risky guess + // that it's UTF-8. + int length = bytes.length; + boolean canBeISO88591 = true; + boolean canBeShiftJIS = true; + boolean canBeUTF8 = true; + int utf8BytesLeft = 0; + int maybeDoubleByteCount = 0; + int maybeSingleByteKatakanaCount = 0; + boolean sawLatin1Supplement = false; + boolean sawUTF8Start = false; + boolean lastWasPossibleDoubleByteStart = false; + + for (int i = 0; + i < length && (canBeISO88591 || canBeShiftJIS || canBeUTF8); + i++) { + + int value = bytes[i] & 0xFF; + + // UTF-8 stuff + if (value >= 0x80 && value <= 0xBF) { + if (utf8BytesLeft > 0) { + utf8BytesLeft--; + } + } else { + if (utf8BytesLeft > 0) { + canBeUTF8 = false; + } + if (value >= 0xC0 && value <= 0xFD) { + sawUTF8Start = true; + int valueCopy = value; + while ((valueCopy & 0x40) != 0) { + utf8BytesLeft++; + valueCopy <<= 1; + } + } + } + + // ISO-8859-1 stuff + + if ((value == 0xC2 || value == 0xC3) && i < length - 1) { + // This is really a poor hack. The slightly more exotic characters people might want to put in + // a QR Code, by which I mean the Latin-1 supplement characters (e.g. u-umlaut) have encodings + // that start with 0xC2 followed by [0xA0,0xBF], or start with 0xC3 followed by [0x80,0xBF]. + int nextValue = bytes[i + 1] & 0xFF; + if (nextValue <= 0xBF && + ((value == 0xC2 && nextValue >= 0xA0) || (value == 0xC3 && nextValue >= 0x80))) { + sawLatin1Supplement = true; + } + } + if (value >= 0x7F && value <= 0x9F) { + canBeISO88591 = false; + } + + // Shift_JIS stuff + + if (value >= 0xA1 && value <= 0xDF) { + // count the number of characters that might be a Shift_JIS single-byte Katakana character + if (!lastWasPossibleDoubleByteStart) { + maybeSingleByteKatakanaCount++; + } + } + if (!lastWasPossibleDoubleByteStart && + ((value >= 0xF0 && value <= 0xFF) || value == 0x80 || value == 0xA0)) { + canBeShiftJIS = false; + } + if ((value >= 0x81 && value <= 0x9F) || (value >= 0xE0 && value <= 0xEF)) { + // These start double-byte characters in Shift_JIS. Let's see if it's followed by a valid + // second byte. + if (lastWasPossibleDoubleByteStart) { + // If we just checked this and the last byte for being a valid double-byte + // char, don't check starting on this byte. If this and the last byte + // formed a valid pair, then this shouldn't be checked to see if it starts + // a double byte pair of course. + lastWasPossibleDoubleByteStart = false; + } else { + // ... otherwise do check to see if this plus the next byte form a valid + // double byte pair encoding a character. + lastWasPossibleDoubleByteStart = true; + if (i >= bytes.length - 1) { + canBeShiftJIS = false; + } else { + int nextValue = bytes[i + 1] & 0xFF; + if (nextValue < 0x40 || nextValue > 0xFC) { + canBeShiftJIS = false; + } else { + maybeDoubleByteCount++; + } + // There is some conflicting information out there about which bytes can follow which in + // double-byte Shift_JIS characters. The rule above seems to be the one that matches practice. + } + } + } else { + lastWasPossibleDoubleByteStart = false; + } + } + if (utf8BytesLeft > 0) { + canBeUTF8 = false; + } + + // Easy -- if assuming Shift_JIS and no evidence it can't be, done + if (canBeShiftJIS && ASSUME_SHIFT_JIS) { + return SHIFT_JIS; + } + if (canBeUTF8 && sawUTF8Start) { + return UTF8; + } + // Distinguishing Shift_JIS and ISO-8859-1 can be a little tough. The crude heuristic is: + // - If we saw + // - at least 3 bytes that starts a double-byte value (bytes that are rare in ISO-8859-1), or + // - over 5% of bytes could be single-byte Katakana (also rare in ISO-8859-1), + // - and, saw no sequences that are invalid in Shift_JIS, then we conclude Shift_JIS + if (canBeShiftJIS && (maybeDoubleByteCount >= 3 || 20 * maybeSingleByteKatakanaCount > length)) { + return SHIFT_JIS; + } + // Otherwise, we default to ISO-8859-1 unless we know it can't be + if (!sawLatin1Supplement && canBeISO88591) { + return ISO88591; + } + // Otherwise, we take a wild guess with platform encoding + return PLATFORM_DEFAULT_ENCODING; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java b/libraries/zxing/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java new file mode 100644 index 000000000..950a22364 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java @@ -0,0 +1,209 @@ +/* + * Copyright 2009 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.detector; + +import com.google.zxing.NotFoundException; +import com.google.zxing.ResultPoint; +import com.google.zxing.common.BitMatrix; + +/** + * <p>A somewhat generic detector that looks for a barcode-like rectangular region within an image. + * It looks within a mostly white region of an image for a region of black and white, but mostly + * black. It returns the four corners of the region, as best it can determine.</p> + * + * @author Sean Owen + */ +public final class MonochromeRectangleDetector { + + private static final int MAX_MODULES = 32; + + private final BitMatrix image; + + public MonochromeRectangleDetector(BitMatrix image) { + this.image = image; + } + + /** + * <p>Detects a rectangular region of black and white -- mostly black -- with a region of mostly + * white, in an image.</p> + * + * @return {@link ResultPoint}[] describing the corners of the rectangular region. The first and + * last points are opposed on the diagonal, as are the second and third. The first point will be + * the topmost point and the last, the bottommost. The second point will be leftmost and the + * third, the rightmost + * @throws NotFoundException if no Data Matrix Code can be found + */ + public ResultPoint[] detect() throws NotFoundException { + int height = image.getHeight(); + int width = image.getWidth(); + int halfHeight = height >> 1; + int halfWidth = width >> 1; + int deltaY = Math.max(1, height / (MAX_MODULES << 3)); + int deltaX = Math.max(1, width / (MAX_MODULES << 3)); + + int top = 0; + int bottom = height; + int left = 0; + int right = width; + ResultPoint pointA = findCornerFromCenter(halfWidth, 0, left, right, + halfHeight, -deltaY, top, bottom, halfWidth >> 1); + top = (int) pointA.getY() - 1; + ResultPoint pointB = findCornerFromCenter(halfWidth, -deltaX, left, right, + halfHeight, 0, top, bottom, halfHeight >> 1); + left = (int) pointB.getX() - 1; + ResultPoint pointC = findCornerFromCenter(halfWidth, deltaX, left, right, + halfHeight, 0, top, bottom, halfHeight >> 1); + right = (int) pointC.getX() + 1; + ResultPoint pointD = findCornerFromCenter(halfWidth, 0, left, right, + halfHeight, deltaY, top, bottom, halfWidth >> 1); + bottom = (int) pointD.getY() + 1; + + // Go try to find point A again with better information -- might have been off at first. + pointA = findCornerFromCenter(halfWidth, 0, left, right, + halfHeight, -deltaY, top, bottom, halfWidth >> 2); + + return new ResultPoint[] { pointA, pointB, pointC, pointD }; + } + + /** + * Attempts to locate a corner of the barcode by scanning up, down, left or right from a center + * point which should be within the barcode. + * + * @param centerX center's x component (horizontal) + * @param deltaX same as deltaY but change in x per step instead + * @param left minimum value of x + * @param right maximum value of x + * @param centerY center's y component (vertical) + * @param deltaY change in y per step. If scanning up this is negative; down, positive; + * left or right, 0 + * @param top minimum value of y to search through (meaningless when di == 0) + * @param bottom maximum value of y + * @param maxWhiteRun maximum run of white pixels that can still be considered to be within + * the barcode + * @return a {@link com.google.zxing.ResultPoint} encapsulating the corner that was found + * @throws NotFoundException if such a point cannot be found + */ + private ResultPoint findCornerFromCenter(int centerX, int deltaX, int left, int right, + int centerY, int deltaY, int top, int bottom, int maxWhiteRun) throws NotFoundException { + int[] lastRange = null; + for (int y = centerY, x = centerX; + y < bottom && y >= top && x < right && x >= left; + y += deltaY, x += deltaX) { + int[] range; + if (deltaX == 0) { + // horizontal slices, up and down + range = blackWhiteRange(y, maxWhiteRun, left, right, true); + } else { + // vertical slices, left and right + range = blackWhiteRange(x, maxWhiteRun, top, bottom, false); + } + if (range == null) { + if (lastRange == null) { + throw NotFoundException.getNotFoundInstance(); + } + // lastRange was found + if (deltaX == 0) { + int lastY = y - deltaY; + if (lastRange[0] < centerX) { + if (lastRange[1] > centerX) { + // straddle, choose one or the other based on direction + return new ResultPoint(deltaY > 0 ? lastRange[0] : lastRange[1], lastY); + } + return new ResultPoint(lastRange[0], lastY); + } else { + return new ResultPoint(lastRange[1], lastY); + } + } else { + int lastX = x - deltaX; + if (lastRange[0] < centerY) { + if (lastRange[1] > centerY) { + return new ResultPoint(lastX, deltaX < 0 ? lastRange[0] : lastRange[1]); + } + return new ResultPoint(lastX, lastRange[0]); + } else { + return new ResultPoint(lastX, lastRange[1]); + } + } + } + lastRange = range; + } + throw NotFoundException.getNotFoundInstance(); + } + + /** + * Computes the start and end of a region of pixels, either horizontally or vertically, that could + * be part of a Data Matrix barcode. + * + * @param fixedDimension if scanning horizontally, this is the row (the fixed vertical location) + * where we are scanning. If scanning vertically it's the column, the fixed horizontal location + * @param maxWhiteRun largest run of white pixels that can still be considered part of the + * barcode region + * @param minDim minimum pixel location, horizontally or vertically, to consider + * @param maxDim maximum pixel location, horizontally or vertically, to consider + * @param horizontal if true, we're scanning left-right, instead of up-down + * @return int[] with start and end of found range, or null if no such range is found + * (e.g. only white was found) + */ + private int[] blackWhiteRange(int fixedDimension, int maxWhiteRun, int minDim, int maxDim, + boolean horizontal) { + + int center = (minDim + maxDim) >> 1; + + // Scan left/up first + int start = center; + while (start >= minDim) { + if (horizontal ? image.get(start, fixedDimension) : image.get(fixedDimension, start)) { + start--; + } else { + int whiteRunStart = start; + do { + start--; + } while (start >= minDim && !(horizontal ? image.get(start, fixedDimension) : + image.get(fixedDimension, start))); + int whiteRunSize = whiteRunStart - start; + if (start < minDim || whiteRunSize > maxWhiteRun) { + start = whiteRunStart; + break; + } + } + } + start++; + + // Then try right/down + int end = center; + while (end < maxDim) { + if (horizontal ? image.get(end, fixedDimension) : image.get(fixedDimension, end)) { + end++; + } else { + int whiteRunStart = end; + do { + end++; + } while (end < maxDim && !(horizontal ? image.get(end, fixedDimension) : + image.get(fixedDimension, end))); + int whiteRunSize = end - whiteRunStart; + if (end >= maxDim || whiteRunSize > maxWhiteRun) { + end = whiteRunStart; + break; + } + } + } + end--; + + return end > start ? new int[]{start, end} : null; + } + +}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/detector/WhiteRectangleDetector.java b/libraries/zxing/src/com/google/zxing/common/detector/WhiteRectangleDetector.java new file mode 100644 index 000000000..31d87e9d0 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/detector/WhiteRectangleDetector.java @@ -0,0 +1,347 @@ +/* + * Copyright 2010 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.detector; + +import com.google.zxing.NotFoundException; +import com.google.zxing.ResultPoint; +import com.google.zxing.common.BitMatrix; + +/** + * <p> + * Detects a candidate barcode-like rectangular region within an image. It + * starts around the center of the image, increases the size of the candidate + * region until it finds a white rectangular region. By keeping track of the + * last black points it encountered, it determines the corners of the barcode. + * </p> + * + * @author David Olivier + */ +public final class WhiteRectangleDetector { + + private static final int INIT_SIZE = 30; + private static final int CORR = 1; + + private final BitMatrix image; + private final int height; + private final int width; + private final int leftInit; + private final int rightInit; + private final int downInit; + private final int upInit; + + /** + * @throws NotFoundException if image is too small + */ + public WhiteRectangleDetector(BitMatrix image) throws NotFoundException { + this.image = image; + height = image.getHeight(); + width = image.getWidth(); + leftInit = (width - INIT_SIZE) >> 1; + rightInit = (width + INIT_SIZE) >> 1; + upInit = (height - INIT_SIZE) >> 1; + downInit = (height + INIT_SIZE) >> 1; + if (upInit < 0 || leftInit < 0 || downInit >= height || rightInit >= width) { + throw NotFoundException.getNotFoundInstance(); + } + } + + /** + * @throws NotFoundException if image is too small + */ + public WhiteRectangleDetector(BitMatrix image, int initSize, int x, int y) throws NotFoundException { + this.image = image; + height = image.getHeight(); + width = image.getWidth(); + int halfsize = initSize >> 1; + leftInit = x - halfsize; + rightInit = x + halfsize; + upInit = y - halfsize; + downInit = y + halfsize; + if (upInit < 0 || leftInit < 0 || downInit >= height || rightInit >= width) { + throw NotFoundException.getNotFoundInstance(); + } + } + + /** + * <p> + * Detects a candidate barcode-like rectangular region within an image. It + * starts around the center of the image, increases the size of the candidate + * region until it finds a white rectangular region. + * </p> + * + * @return {@link ResultPoint[]} describing the corners of the rectangular + * region. The first and last points are opposed on the diagonal, as + * are the second and third. The first point will be the topmost + * point and the last, the bottommost. The second point will be + * leftmost and the third, the rightmost + * @throws NotFoundException if no Data Matrix Code can be found + */ + public ResultPoint[] detect() throws NotFoundException { + + int left = leftInit; + int right = rightInit; + int up = upInit; + int down = downInit; + boolean sizeExceeded = false; + boolean aBlackPointFoundOnBorder = true; + boolean atLeastOneBlackPointFoundOnBorder = false; + + while (aBlackPointFoundOnBorder) { + + aBlackPointFoundOnBorder = false; + + // ..... + // . | + // ..... + boolean rightBorderNotWhite = true; + while (rightBorderNotWhite && right < width) { + rightBorderNotWhite = containsBlackPoint(up, down, right, false); + if (rightBorderNotWhite) { + right++; + aBlackPointFoundOnBorder = true; + } + } + + if (right >= width) { + sizeExceeded = true; + break; + } + + // ..... + // . . + // .___. + boolean bottomBorderNotWhite = true; + while (bottomBorderNotWhite && down < height) { + bottomBorderNotWhite = containsBlackPoint(left, right, down, true); + if (bottomBorderNotWhite) { + down++; + aBlackPointFoundOnBorder = true; + } + } + + if (down >= height) { + sizeExceeded = true; + break; + } + + // ..... + // | . + // ..... + boolean leftBorderNotWhite = true; + while (leftBorderNotWhite && left >= 0) { + leftBorderNotWhite = containsBlackPoint(up, down, left, false); + if (leftBorderNotWhite) { + left--; + aBlackPointFoundOnBorder = true; + } + } + + if (left < 0) { + sizeExceeded = true; + break; + } + + // .___. + // . . + // ..... + boolean topBorderNotWhite = true; + while (topBorderNotWhite && up >= 0) { + topBorderNotWhite = containsBlackPoint(left, right, up, true); + if (topBorderNotWhite) { + up--; + aBlackPointFoundOnBorder = true; + } + } + + if (up < 0) { + sizeExceeded = true; + break; + } + + if (aBlackPointFoundOnBorder) { + atLeastOneBlackPointFoundOnBorder = true; + } + + } + + if (!sizeExceeded && atLeastOneBlackPointFoundOnBorder) { + + int maxSize = right - left; + + ResultPoint z = null; + for (int i = 1; i < maxSize; i++) { + z = getBlackPointOnSegment(left, down - i, left + i, down); + if (z != null) { + break; + } + } + + if (z == null) { + throw NotFoundException.getNotFoundInstance(); + } + + ResultPoint t = null; + //go down right + for (int i = 1; i < maxSize; i++) { + t = getBlackPointOnSegment(left, up + i, left + i, up); + if (t != null) { + break; + } + } + + if (t == null) { + throw NotFoundException.getNotFoundInstance(); + } + + ResultPoint x = null; + //go down left + for (int i = 1; i < maxSize; i++) { + x = getBlackPointOnSegment(right, up + i, right - i, up); + if (x != null) { + break; + } + } + + if (x == null) { + throw NotFoundException.getNotFoundInstance(); + } + + ResultPoint y = null; + //go up left + for (int i = 1; i < maxSize; i++) { + y = getBlackPointOnSegment(right, down - i, right - i, down); + if (y != null) { + break; + } + } + + if (y == null) { + throw NotFoundException.getNotFoundInstance(); + } + + return centerEdges(y, z, x, t); + + } else { + throw NotFoundException.getNotFoundInstance(); + } + } + + /** + * Ends up being a bit faster than Math.round(). This merely rounds its + * argument to the nearest int, where x.5 rounds up. + */ + private static int round(float d) { + return (int) (d + 0.5f); + } + + private ResultPoint getBlackPointOnSegment(float aX, float aY, float bX, float bY) { + int dist = distanceL2(aX, aY, bX, bY); + float xStep = (bX - aX) / dist; + float yStep = (bY - aY) / dist; + + for (int i = 0; i < dist; i++) { + int x = round(aX + i * xStep); + int y = round(aY + i * yStep); + if (image.get(x, y)) { + return new ResultPoint(x, y); + } + } + return null; + } + + private static int distanceL2(float aX, float aY, float bX, float bY) { + float xDiff = aX - bX; + float yDiff = aY - bY; + return round((float) Math.sqrt(xDiff * xDiff + yDiff * yDiff)); + } + + /** + * recenters the points of a constant distance towards the center + * + * @param y bottom most point + * @param z left most point + * @param x right most point + * @param t top most point + * @return {@link ResultPoint}[] describing the corners of the rectangular + * region. The first and last points are opposed on the diagonal, as + * are the second and third. The first point will be the topmost + * point and the last, the bottommost. The second point will be + * leftmost and the third, the rightmost + */ + private ResultPoint[] centerEdges(ResultPoint y, ResultPoint z, + ResultPoint x, ResultPoint t) { + + // + // t t + // z x + // x OR z + // y y + // + + float yi = y.getX(); + float yj = y.getY(); + float zi = z.getX(); + float zj = z.getY(); + float xi = x.getX(); + float xj = x.getY(); + float ti = t.getX(); + float tj = t.getY(); + + if (yi < width / 2) { + return new ResultPoint[]{ + new ResultPoint(ti - CORR, tj + CORR), + new ResultPoint(zi + CORR, zj + CORR), + new ResultPoint(xi - CORR, xj - CORR), + new ResultPoint(yi + CORR, yj - CORR)}; + } else { + return new ResultPoint[]{ + new ResultPoint(ti + CORR, tj + CORR), + new ResultPoint(zi + CORR, zj - CORR), + new ResultPoint(xi - CORR, xj + CORR), + new ResultPoint(yi - CORR, yj - CORR)}; + } + } + + /** + * Determines whether a segment contains a black point + * + * @param a min value of the scanned coordinate + * @param b max value of the scanned coordinate + * @param fixed value of fixed coordinate + * @param horizontal set to true if scan must be horizontal, false if vertical + * @return true if a black point has been found, else false. + */ + private boolean containsBlackPoint(int a, int b, int fixed, boolean horizontal) { + + if (horizontal) { + for (int x = a; x <= b; x++) { + if (image.get(x, fixed)) { + return true; + } + } + } else { + for (int y = a; y <= b; y++) { + if (image.get(fixed, y)) { + return true; + } + } + } + + return false; + } + +}
\ No newline at end of file diff --git a/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGF.java b/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGF.java new file mode 100644 index 000000000..859c379ee --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGF.java @@ -0,0 +1,188 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.reedsolomon; + +/** + * <p>This class contains utility methods for performing mathematical operations over + * the Galois Fields. Operations use a given primitive polynomial in calculations.</p> + * + * <p>Throughout this package, elements of the GF are represented as an <code>int</code> + * for convenience and speed (but at the cost of memory). + * </p> + * + * @author Sean Owen + * @author David Olivier + */ +public final class GenericGF { + + public static final GenericGF AZTEC_DATA_12 = new GenericGF(0x1069, 4096); // x^12 + x^6 + x^5 + x^3 + 1 + public static final GenericGF AZTEC_DATA_10 = new GenericGF(0x409, 1024); // x^10 + x^3 + 1 + public static final GenericGF AZTEC_DATA_6 = new GenericGF(0x43, 64); // x^6 + x + 1 + public static final GenericGF AZTEC_PARAM = new GenericGF(0x13, 16); // x^4 + x + 1 + public static final GenericGF QR_CODE_FIELD_256 = new GenericGF(0x011D, 256); // x^8 + x^4 + x^3 + x^2 + 1 + public static final GenericGF DATA_MATRIX_FIELD_256 = new GenericGF(0x012D, 256); // x^8 + x^5 + x^3 + x^2 + 1 + public static final GenericGF AZTEC_DATA_8 = DATA_MATRIX_FIELD_256; + + private static final int INITIALIZATION_THRESHOLD = 0; + + private int[] expTable; + private int[] logTable; + private GenericGFPoly zero; + private GenericGFPoly one; + private final int size; + private final int primitive; + private boolean initialized = false; + + /** + * Create a representation of GF(size) using the given primitive polynomial. + * + * @param primitive irreducible polynomial whose coefficients are represented by + * the bits of an int, where the least-significant bit represents the constant + * coefficient + */ + public GenericGF(int primitive, int size) { + this.primitive = primitive; + this.size = size; + + if (size <= INITIALIZATION_THRESHOLD){ + initialize(); + } + } + + private void initialize(){ + expTable = new int[size]; + logTable = new int[size]; + int x = 1; + for (int i = 0; i < size; i++) { + expTable[i] = x; + x <<= 1; // x = x * 2; we're assuming the generator alpha is 2 + if (x >= size) { + x ^= primitive; + x &= size-1; + } + } + for (int i = 0; i < size-1; i++) { + logTable[expTable[i]] = i; + } + // logTable[0] == 0 but this should never be used + zero = new GenericGFPoly(this, new int[]{0}); + one = new GenericGFPoly(this, new int[]{1}); + initialized = true; + } + + private void checkInit(){ + if (!initialized) { + initialize(); + } + } + + GenericGFPoly getZero() { + checkInit(); + + return zero; + } + + GenericGFPoly getOne() { + checkInit(); + + return one; + } + + /** + * @return the monomial representing coefficient * x^degree + */ + GenericGFPoly buildMonomial(int degree, int coefficient) { + checkInit(); + + if (degree < 0) { + throw new IllegalArgumentException(); + } + if (coefficient == 0) { + return zero; + } + int[] coefficients = new int[degree + 1]; + coefficients[0] = coefficient; + return new GenericGFPoly(this, coefficients); + } + + /** + * Implements both addition and subtraction -- they are the same in GF(size). + * + * @return sum/difference of a and b + */ + static int addOrSubtract(int a, int b) { + return a ^ b; + } + + /** + * @return 2 to the power of a in GF(size) + */ + int exp(int a) { + checkInit(); + + return expTable[a]; + } + + /** + * @return base 2 log of a in GF(size) + */ + int log(int a) { + checkInit(); + + if (a == 0) { + throw new IllegalArgumentException(); + } + return logTable[a]; + } + + /** + * @return multiplicative inverse of a + */ + int inverse(int a) { + checkInit(); + + if (a == 0) { + throw new ArithmeticException(); + } + return expTable[size - logTable[a] - 1]; + } + + /** + * @param a + * @param b + * @return product of a and b in GF(size) + */ + int multiply(int a, int b) { + checkInit(); + + if (a == 0 || b == 0) { + return 0; + } + + if (a<0 || b <0 || a>=size || b >=size){ + a++; + } + + int logSum = logTable[a] + logTable[b]; + return expTable[(logSum % size) + logSum / size]; + } + + public int getSize(){ + return size; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java b/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java new file mode 100644 index 000000000..056802287 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/reedsolomon/GenericGFPoly.java @@ -0,0 +1,263 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.reedsolomon; + +/** + * <p>Represents a polynomial whose coefficients are elements of a GF. + * Instances of this class are immutable.</p> + * + * <p>Much credit is due to William Rucklidge since portions of this code are an indirect + * port of his C++ Reed-Solomon implementation.</p> + * + * @author Sean Owen + */ +final class GenericGFPoly { + + private final GenericGF field; + private final int[] coefficients; + + /** + * @param field the {@link GenericGF} instance representing the field to use + * to perform computations + * @param coefficients coefficients as ints representing elements of GF(size), arranged + * from most significant (highest-power term) coefficient to least significant + * @throws IllegalArgumentException if argument is null or empty, + * or if leading coefficient is 0 and this is not a + * constant polynomial (that is, it is not the monomial "0") + */ + GenericGFPoly(GenericGF field, int[] coefficients) { + if (coefficients == null || coefficients.length == 0) { + throw new IllegalArgumentException(); + } + this.field = field; + int coefficientsLength = coefficients.length; + if (coefficientsLength > 1 && coefficients[0] == 0) { + // Leading term must be non-zero for anything except the constant polynomial "0" + int firstNonZero = 1; + while (firstNonZero < coefficientsLength && coefficients[firstNonZero] == 0) { + firstNonZero++; + } + if (firstNonZero == coefficientsLength) { + this.coefficients = field.getZero().coefficients; + } else { + this.coefficients = new int[coefficientsLength - firstNonZero]; + System.arraycopy(coefficients, + firstNonZero, + this.coefficients, + 0, + this.coefficients.length); + } + } else { + this.coefficients = coefficients; + } + } + + int[] getCoefficients() { + return coefficients; + } + + /** + * @return degree of this polynomial + */ + int getDegree() { + return coefficients.length - 1; + } + + /** + * @return true iff this polynomial is the monomial "0" + */ + boolean isZero() { + return coefficients[0] == 0; + } + + /** + * @return coefficient of x^degree term in this polynomial + */ + int getCoefficient(int degree) { + return coefficients[coefficients.length - 1 - degree]; + } + + /** + * @return evaluation of this polynomial at a given point + */ + int evaluateAt(int a) { + if (a == 0) { + // Just return the x^0 coefficient + return getCoefficient(0); + } + int size = coefficients.length; + if (a == 1) { + // Just the sum of the coefficients + int result = 0; + for (int i = 0; i < size; i++) { + result = GenericGF.addOrSubtract(result, coefficients[i]); + } + return result; + } + int result = coefficients[0]; + for (int i = 1; i < size; i++) { + result = GenericGF.addOrSubtract(field.multiply(a, result), coefficients[i]); + } + return result; + } + + GenericGFPoly addOrSubtract(GenericGFPoly other) { + if (!field.equals(other.field)) { + throw new IllegalArgumentException("GenericGFPolys do not have same GenericGF field"); + } + if (isZero()) { + return other; + } + if (other.isZero()) { + return this; + } + + int[] smallerCoefficients = this.coefficients; + int[] largerCoefficients = other.coefficients; + if (smallerCoefficients.length > largerCoefficients.length) { + int[] temp = smallerCoefficients; + smallerCoefficients = largerCoefficients; + largerCoefficients = temp; + } + int[] sumDiff = new int[largerCoefficients.length]; + int lengthDiff = largerCoefficients.length - smallerCoefficients.length; + // Copy high-order terms only found in higher-degree polynomial's coefficients + System.arraycopy(largerCoefficients, 0, sumDiff, 0, lengthDiff); + + for (int i = lengthDiff; i < largerCoefficients.length; i++) { + sumDiff[i] = GenericGF.addOrSubtract(smallerCoefficients[i - lengthDiff], largerCoefficients[i]); + } + + return new GenericGFPoly(field, sumDiff); + } + + GenericGFPoly multiply(GenericGFPoly other) { + if (!field.equals(other.field)) { + throw new IllegalArgumentException("GenericGFPolys do not have same GenericGF field"); + } + if (isZero() || other.isZero()) { + return field.getZero(); + } + int[] aCoefficients = this.coefficients; + int aLength = aCoefficients.length; + int[] bCoefficients = other.coefficients; + int bLength = bCoefficients.length; + int[] product = new int[aLength + bLength - 1]; + for (int i = 0; i < aLength; i++) { + int aCoeff = aCoefficients[i]; + for (int j = 0; j < bLength; j++) { + product[i + j] = GenericGF.addOrSubtract(product[i + j], + field.multiply(aCoeff, bCoefficients[j])); + } + } + return new GenericGFPoly(field, product); + } + + GenericGFPoly multiply(int scalar) { + if (scalar == 0) { + return field.getZero(); + } + if (scalar == 1) { + return this; + } + int size = coefficients.length; + int[] product = new int[size]; + for (int i = 0; i < size; i++) { + product[i] = field.multiply(coefficients[i], scalar); + } + return new GenericGFPoly(field, product); + } + + GenericGFPoly multiplyByMonomial(int degree, int coefficient) { + if (degree < 0) { + throw new IllegalArgumentException(); + } + if (coefficient == 0) { + return field.getZero(); + } + int size = coefficients.length; + int[] product = new int[size + degree]; + for (int i = 0; i < size; i++) { + product[i] = field.multiply(coefficients[i], coefficient); + } + return new GenericGFPoly(field, product); + } + + GenericGFPoly[] divide(GenericGFPoly other) { + if (!field.equals(other.field)) { + throw new IllegalArgumentException("GenericGFPolys do not have same GenericGF field"); + } + if (other.isZero()) { + throw new IllegalArgumentException("Divide by 0"); + } + + GenericGFPoly quotient = field.getZero(); + GenericGFPoly remainder = this; + + int denominatorLeadingTerm = other.getCoefficient(other.getDegree()); + int inverseDenominatorLeadingTerm = field.inverse(denominatorLeadingTerm); + + while (remainder.getDegree() >= other.getDegree() && !remainder.isZero()) { + int degreeDifference = remainder.getDegree() - other.getDegree(); + int scale = field.multiply(remainder.getCoefficient(remainder.getDegree()), inverseDenominatorLeadingTerm); + GenericGFPoly term = other.multiplyByMonomial(degreeDifference, scale); + GenericGFPoly iterationQuotient = field.buildMonomial(degreeDifference, scale); + quotient = quotient.addOrSubtract(iterationQuotient); + remainder = remainder.addOrSubtract(term); + } + + return new GenericGFPoly[] { quotient, remainder }; + } + + public String toString() { + StringBuffer result = new StringBuffer(8 * getDegree()); + for (int degree = getDegree(); degree >= 0; degree--) { + int coefficient = getCoefficient(degree); + if (coefficient != 0) { + if (coefficient < 0) { + result.append(" - "); + coefficient = -coefficient; + } else { + if (result.length() > 0) { + result.append(" + "); + } + } + if (degree == 0 || coefficient != 1) { + int alphaPower = field.log(coefficient); + if (alphaPower == 0) { + result.append('1'); + } else if (alphaPower == 1) { + result.append('a'); + } else { + result.append("a^"); + result.append(alphaPower); + } + } + if (degree != 0) { + if (degree == 1) { + result.append('x'); + } else { + result.append("x^"); + result.append(degree); + } + } + } + } + return result.toString(); + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonDecoder.java b/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonDecoder.java new file mode 100644 index 000000000..b523fd34b --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonDecoder.java @@ -0,0 +1,194 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.reedsolomon; + +/** + * <p>Implements Reed-Solomon decoding, as the name implies.</p> + * + * <p>The algorithm will not be explained here, but the following references were helpful + * in creating this implementation:</p> + * + * <ul> + * <li>Bruce Maggs. + * <a href="http://www.cs.cmu.edu/afs/cs.cmu.edu/project/pscico-guyb/realworld/www/rs_decode.ps"> + * "Decoding Reed-Solomon Codes"</a> (see discussion of Forney's Formula)</li> + * <li>J.I. Hall. <a href="www.mth.msu.edu/~jhall/classes/codenotes/GRS.pdf"> + * "Chapter 5. Generalized Reed-Solomon Codes"</a> + * (see discussion of Euclidean algorithm)</li> + * </ul> + * + * <p>Much credit is due to William Rucklidge since portions of this code are an indirect + * port of his C++ Reed-Solomon implementation.</p> + * + * @author Sean Owen + * @author William Rucklidge + * @author sanfordsquires + */ +public final class ReedSolomonDecoder { + + private final GenericGF field; + + public ReedSolomonDecoder(GenericGF field) { + this.field = field; + } + + /** + * <p>Decodes given set of received codewords, which include both data and error-correction + * codewords. Really, this means it uses Reed-Solomon to detect and correct errors, in-place, + * in the input.</p> + * + * @param received data and error-correction codewords + * @param twoS number of error-correction codewords available + * @throws ReedSolomonException if decoding fails for any reason + */ + public void decode(int[] received, int twoS) throws ReedSolomonException { + GenericGFPoly poly = new GenericGFPoly(field, received); + int[] syndromeCoefficients = new int[twoS]; + boolean dataMatrix = field.equals(GenericGF.DATA_MATRIX_FIELD_256); + boolean noError = true; + for (int i = 0; i < twoS; i++) { + // Thanks to sanfordsquires for this fix: + int eval = poly.evaluateAt(field.exp(dataMatrix ? i + 1 : i)); + syndromeCoefficients[syndromeCoefficients.length - 1 - i] = eval; + if (eval != 0) { + noError = false; + } + } + if (noError) { + return; + } + GenericGFPoly syndrome = new GenericGFPoly(field, syndromeCoefficients); + GenericGFPoly[] sigmaOmega = + runEuclideanAlgorithm(field.buildMonomial(twoS, 1), syndrome, twoS); + GenericGFPoly sigma = sigmaOmega[0]; + GenericGFPoly omega = sigmaOmega[1]; + int[] errorLocations = findErrorLocations(sigma); + int[] errorMagnitudes = findErrorMagnitudes(omega, errorLocations, dataMatrix); + for (int i = 0; i < errorLocations.length; i++) { + int position = received.length - 1 - field.log(errorLocations[i]); + if (position < 0) { + throw new ReedSolomonException("Bad error location"); + } + received[position] = GenericGF.addOrSubtract(received[position], errorMagnitudes[i]); + } + } + + private GenericGFPoly[] runEuclideanAlgorithm(GenericGFPoly a, GenericGFPoly b, int R) + throws ReedSolomonException { + // Assume a's degree is >= b's + if (a.getDegree() < b.getDegree()) { + GenericGFPoly temp = a; + a = b; + b = temp; + } + + GenericGFPoly rLast = a; + GenericGFPoly r = b; + GenericGFPoly sLast = field.getOne(); + GenericGFPoly s = field.getZero(); + GenericGFPoly tLast = field.getZero(); + GenericGFPoly t = field.getOne(); + + // Run Euclidean algorithm until r's degree is less than R/2 + while (r.getDegree() >= R / 2) { + GenericGFPoly rLastLast = rLast; + GenericGFPoly sLastLast = sLast; + GenericGFPoly tLastLast = tLast; + rLast = r; + sLast = s; + tLast = t; + + // Divide rLastLast by rLast, with quotient in q and remainder in r + if (rLast.isZero()) { + // Oops, Euclidean algorithm already terminated? + throw new ReedSolomonException("r_{i-1} was zero"); + } + r = rLastLast; + GenericGFPoly q = field.getZero(); + int denominatorLeadingTerm = rLast.getCoefficient(rLast.getDegree()); + int dltInverse = field.inverse(denominatorLeadingTerm); + while (r.getDegree() >= rLast.getDegree() && !r.isZero()) { + int degreeDiff = r.getDegree() - rLast.getDegree(); + int scale = field.multiply(r.getCoefficient(r.getDegree()), dltInverse); + q = q.addOrSubtract(field.buildMonomial(degreeDiff, scale)); + r = r.addOrSubtract(rLast.multiplyByMonomial(degreeDiff, scale)); + } + + s = q.multiply(sLast).addOrSubtract(sLastLast); + t = q.multiply(tLast).addOrSubtract(tLastLast); + } + + int sigmaTildeAtZero = t.getCoefficient(0); + if (sigmaTildeAtZero == 0) { + throw new ReedSolomonException("sigmaTilde(0) was zero"); + } + + int inverse = field.inverse(sigmaTildeAtZero); + GenericGFPoly sigma = t.multiply(inverse); + GenericGFPoly omega = r.multiply(inverse); + return new GenericGFPoly[]{sigma, omega}; + } + + private int[] findErrorLocations(GenericGFPoly errorLocator) throws ReedSolomonException { + // This is a direct application of Chien's search + int numErrors = errorLocator.getDegree(); + if (numErrors == 1) { // shortcut + return new int[] { errorLocator.getCoefficient(1) }; + } + int[] result = new int[numErrors]; + int e = 0; + for (int i = 1; i < field.getSize() && e < numErrors; i++) { + if (errorLocator.evaluateAt(i) == 0) { + result[e] = field.inverse(i); + e++; + } + } + if (e != numErrors) { + throw new ReedSolomonException("Error locator degree does not match number of roots"); + } + return result; + } + + private int[] findErrorMagnitudes(GenericGFPoly errorEvaluator, int[] errorLocations, boolean dataMatrix) { + // This is directly applying Forney's Formula + int s = errorLocations.length; + int[] result = new int[s]; + for (int i = 0; i < s; i++) { + int xiInverse = field.inverse(errorLocations[i]); + int denominator = 1; + for (int j = 0; j < s; j++) { + if (i != j) { + //denominator = field.multiply(denominator, + // GenericGF.addOrSubtract(1, field.multiply(errorLocations[j], xiInverse))); + // Above should work but fails on some Apple and Linux JDKs due to a Hotspot bug. + // Below is a funny-looking workaround from Steven Parkes + int term = field.multiply(errorLocations[j], xiInverse); + int termPlus1 = (term & 0x1) == 0 ? term | 1 : term & ~1; + denominator = field.multiply(denominator, termPlus1); + } + } + result[i] = field.multiply(errorEvaluator.evaluateAt(xiInverse), + field.inverse(denominator)); + // Thanks to sanfordsquires for this fix: + if (dataMatrix) { + result[i] = field.multiply(result[i], xiInverse); + } + } + return result; + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonEncoder.java b/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonEncoder.java new file mode 100644 index 000000000..05e2ae03a --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonEncoder.java @@ -0,0 +1,75 @@ +/* + * Copyright 2008 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.reedsolomon; + +import java.util.Vector; + +/** + * <p>Implements Reed-Solomon enbcoding, as the name implies.</p> + * + * @author Sean Owen + * @author William Rucklidge + */ +public final class ReedSolomonEncoder { + + private final GenericGF field; + private final Vector cachedGenerators; + + public ReedSolomonEncoder(GenericGF field) { + if (!GenericGF.QR_CODE_FIELD_256.equals(field)) { + throw new IllegalArgumentException("Only QR Code is supported at this time"); + } + this.field = field; + this.cachedGenerators = new Vector(); + cachedGenerators.addElement(new GenericGFPoly(field, new int[] { 1 })); + } + + private GenericGFPoly buildGenerator(int degree) { + if (degree >= cachedGenerators.size()) { + GenericGFPoly lastGenerator = (GenericGFPoly) cachedGenerators.elementAt(cachedGenerators.size() - 1); + for (int d = cachedGenerators.size(); d <= degree; d++) { + GenericGFPoly nextGenerator = lastGenerator.multiply(new GenericGFPoly(field, new int[] { 1, field.exp(d - 1) })); + cachedGenerators.addElement(nextGenerator); + lastGenerator = nextGenerator; + } + } + return (GenericGFPoly) cachedGenerators.elementAt(degree); + } + + public void encode(int[] toEncode, int ecBytes) { + if (ecBytes == 0) { + throw new IllegalArgumentException("No error correction bytes"); + } + int dataBytes = toEncode.length - ecBytes; + if (dataBytes <= 0) { + throw new IllegalArgumentException("No data bytes provided"); + } + GenericGFPoly generator = buildGenerator(ecBytes); + int[] infoCoefficients = new int[dataBytes]; + System.arraycopy(toEncode, 0, infoCoefficients, 0, dataBytes); + GenericGFPoly info = new GenericGFPoly(field, infoCoefficients); + info = info.multiplyByMonomial(ecBytes, 1); + GenericGFPoly remainder = info.divide(generator)[1]; + int[] coefficients = remainder.getCoefficients(); + int numZeroCoefficients = ecBytes - coefficients.length; + for (int i = 0; i < numZeroCoefficients; i++) { + toEncode[dataBytes + i] = 0; + } + System.arraycopy(coefficients, 0, toEncode, dataBytes + numZeroCoefficients, coefficients.length); + } + +} diff --git a/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonException.java b/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonException.java new file mode 100644 index 000000000..d5b45a612 --- /dev/null +++ b/libraries/zxing/src/com/google/zxing/common/reedsolomon/ReedSolomonException.java @@ -0,0 +1,31 @@ +/* + * Copyright 2007 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.common.reedsolomon; + +/** + * <p>Thrown when an exception occurs during Reed-Solomon decoding, such as when + * there are too many errors to correct.</p> + * + * @author Sean Owen + */ +public final class ReedSolomonException extends Exception { + + public ReedSolomonException(String message) { + super(message); + } + +}
\ No newline at end of file |