2 * Copyright (C) 2008 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 android.graphics.Bitmap;
20 import android.graphics.Rect;
21 import com.google.zxing.common.BaseMonochromeBitmapSource;
24 * This object implements MonochromeBitmapSource around an array of YUV data, giving you the option
25 * to crop to a rectangle within the full data. This can be used to exclude superfluous pixels
26 * around the perimeter and speed up decoding.
28 final class YUVMonochromeBitmapSource extends BaseMonochromeBitmapSource {
30 private final byte[] mYUVData;
31 private final int mDataWidth;
32 private final Rect mCrop;
35 * Builds an object around a YUV buffer from the camera.
37 * @param yuvData A byte array of planar Y data, followed by interleaved U and V
38 * @param dataWidth The width of the Y data
39 * @param dataHeight The height of the Y data
40 * @param crop The rectangle within the yuvData to expose to MonochromeBitmapSource users
42 YUVMonochromeBitmapSource(byte[] yuvData, int dataWidth, int dataHeight, Rect crop) {
43 if (crop.width() > dataWidth || crop.height() > dataHeight) {
44 throw new IllegalArgumentException();
47 mDataWidth = dataWidth;
52 public int getHeight() {
53 return mCrop.height();
57 public int getWidth() {
62 * The Y channel is stored as planar data at the head of the array, so we just ignore the
63 * interleavd U and V which follow it.
65 * @param x The x coordinate to fetch within crop
66 * @param y The y coordinate to fetch within crop
67 * @return The luminance as an int, from 0-255
70 protected int getLuminance(int x, int y) {
71 return mYUVData[(y + mCrop.top) * mDataWidth + x + mCrop.left] & 0xff;
75 protected int[] getLuminanceRow(int y, int[] row) {
76 int width = getWidth();
77 if (row == null || row.length < width) {
80 int offset = (y + mCrop.top) * mDataWidth + mCrop.left;
81 for (int x = 0; x < width; x++) {
82 row[x] = mYUVData[offset + x] & 0xff;
88 protected int[] getLuminanceColumn(int x, int[] column) {
89 int height = getHeight();
90 if (column == null || column.length < height) {
91 column = new int[height];
93 int offset = mCrop.top * mDataWidth + mCrop.left + x;
94 for (int y = 0; y < height; y++) {
95 column[y] = mYUVData[offset] & 0xff;
102 * Create a greyscale Android Bitmap from the YUV data based on the crop rectangle.
104 * @return An 8888 bitmap.
106 public Bitmap renderToBitmap() {
107 int width = mCrop.width();
108 int height = mCrop.height();
109 int[] pixels = new int[width * height];
110 for (int y = 0; y < height; y++) {
111 int base = (y + mCrop.top) * mDataWidth + mCrop.left;
112 for (int x = 0; x < width; x++) {
113 int grey = mYUVData[base + x] & 0xff;
114 pixels[y * width + x] = (0xff << 24) | (grey << 16) | (grey << 8) | grey;
118 Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
119 bitmap.setPixels(pixels, 0, width, 0, 0, width, height);