1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
/*
* 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;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.BitMatrix;
/**
* This class is the core bitmap class used by ZXing to represent 1 bit data. Reader objects
* accept a BinaryBitmap and attempt to decode it.
*
* @author dswitkin@google.com (Daniel Switkin)
*/
public final class BinaryBitmap {
private final Binarizer binarizer;
private BitMatrix matrix;
public BinaryBitmap(Binarizer binarizer) {
if (binarizer == null) {
throw new IllegalArgumentException("Binarizer must be non-null.");
}
this.binarizer = binarizer;
matrix = null;
}
/**
* @return The width of the bitmap.
*/
public int getWidth() {
return binarizer.getLuminanceSource().getWidth();
}
/**
* @return The height of the bitmap.
*/
public int getHeight() {
return binarizer.getLuminanceSource().getHeight();
}
/**
* Converts one row of luminance data to 1 bit data. May actually do the conversion, or return
* cached data. Callers should assume this method is expensive and call it as seldom as possible.
* This method is intended for decoding 1D barcodes and may choose to apply sharpening.
*
* @param y The row to fetch, 0 <= y < bitmap height.
* @param row An optional preallocated array. If null or too small, it will be ignored.
* If used, the Binarizer will call BitArray.clear(). Always use the returned object.
* @return The array of bits for this row (true means black).
*/
public BitArray getBlackRow(int y, BitArray row) throws NotFoundException {
return binarizer.getBlackRow(y, row);
}
/**
* Converts a 2D array of luminance data to 1 bit. As above, assume this method is expensive
* and do not call it repeatedly. This method is intended for decoding 2D barcodes and may or
* may not apply sharpening. Therefore, a row from this matrix may not be identical to one
* fetched using getBlackRow(), so don't mix and match between them.
*
* @return The 2D array of bits for the image (true means black).
*/
public BitMatrix getBlackMatrix() throws NotFoundException {
// The matrix is created on demand the first time it is requested, then cached. There are two
// reasons for this:
// 1. This work will never be done if the caller only installs 1D Reader objects, or if a
// 1D Reader finds a barcode before the 2D Readers run.
// 2. This work will only be done once even if the caller installs multiple 2D Readers.
if (matrix == null) {
matrix = binarizer.getBlackMatrix();
}
return matrix;
}
/**
* @return Whether this bitmap can be cropped.
*/
public boolean isCropSupported() {
return binarizer.getLuminanceSource().isCropSupported();
}
/**
* Returns a new object with cropped image data. Implementations may keep a reference to the
* original data rather than a copy. Only callable if isCropSupported() is true.
*
* @param left The left coordinate, 0 <= left < getWidth().
* @param top The top coordinate, 0 <= top <= getHeight().
* @param width The width of the rectangle to crop.
* @param height The height of the rectangle to crop.
* @return A cropped version of this object.
*/
public BinaryBitmap crop(int left, int top, int width, int height) {
LuminanceSource newSource = binarizer.getLuminanceSource().crop(left, top, width, height);
return new BinaryBitmap(binarizer.createBinarizer(newSource));
}
/**
* @return Whether this bitmap supports counter-clockwise rotation.
*/
public boolean isRotateSupported() {
return binarizer.getLuminanceSource().isRotateSupported();
}
/**
* Returns a new object with rotated image data. Only callable if isRotateSupported() is true.
*
* @return A rotated version of this object.
*/
public BinaryBitmap rotateCounterClockwise() {
LuminanceSource newSource = binarizer.getLuminanceSource().rotateCounterClockwise();
return new BinaryBitmap(binarizer.createBinarizer(newSource));
}
}
|
