2 * Copyright 2009 ZXing authors
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing.client.android;
19 import com.google.zxing.LuminanceSource;
21 import android.graphics.Bitmap;
24 * This object extends LuminanceSource around an array of YUV data returned from the camera driver,
25 * with the option to crop to a rectangle within the full data. This can be used to exclude
26 * superfluous pixels around the perimeter and speed up decoding.
28 * @author dswitkin@google.com (Daniel Switkin)
30 public final class YUVLuminanceSource extends LuminanceSource {
32 private final byte[] yuvData;
33 private final int dataWidth;
34 private final int dataHeight;
35 private final int left;
36 private final int top;
38 public YUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left, int top,
39 int width, int height) {
42 if (left + width > dataWidth || top + height > dataHeight) {
43 throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
46 this.yuvData = yuvData;
47 this.dataWidth = dataWidth;
48 this.dataHeight = dataHeight;
53 public byte[] getRow(int y, byte[] row) {
54 if (y < 0 || y >= getHeight()) {
55 throw new IllegalArgumentException("Requested row is outside the image: " + y);
57 int width = getWidth();
58 if (row == null || row.length < width) {
59 row = new byte[width];
61 int offset = (y + top) * dataWidth + left;
62 System.arraycopy(yuvData, offset, row, 0, width);
66 public byte[] getMatrix() {
67 int width = getWidth();
68 int height = getHeight();
70 // If the caller asks for the entire underlying image, save the copy and give them the
71 // original data. The docs specifically warn that result.length must be ignored.
72 if (width == dataWidth && height == dataHeight) {
76 int area = width * height;
77 byte[] matrix = new byte[area];
78 int inputOffset = top * dataWidth + left;
80 // If the width matches the full width of the underlying data, perform a single copy.
81 if (width == dataWidth) {
82 System.arraycopy(yuvData, inputOffset, matrix, 0, area);
86 // Otherwise copy one cropped row at a time.
88 for (int y = 0; y < height; y++) {
89 int outputOffset = y * width;
90 System.arraycopy(yuv, inputOffset, matrix, outputOffset, width);
91 inputOffset += dataWidth;
96 public boolean isCropSupported() {
100 public LuminanceSource crop(int left, int top, int width, int height) {
101 return new YUVLuminanceSource(yuvData, dataWidth, dataHeight, left, top, width, height);
105 * Creates a greyscale Android Bitmap from the YUV data based on the crop rectangle.
107 * @return An 8888 bitmap.
109 public Bitmap renderToBitmap() {
110 int width = getWidth();
111 int height = getHeight();
112 int[] pixels = new int[width * height];
113 byte[] yuv = yuvData;
114 int inputOffset = top * dataWidth + left;
116 for (int y = 0; y < height; y++) {
117 int outputOffset = y * width;
118 for (int x = 0; x < width; x++) {
119 int grey = yuv[inputOffset + x] & 0xff;
120 pixels[outputOffset + x] = (0xff << 24) | (grey << 16) | (grey << 8) | grey;
122 inputOffset += dataWidth;
125 Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
126 bitmap.setPixels(pixels, 0, width, 0, 0, width, height);