Android Open Source - esr-scanner Planar Y U V Luminance Source

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The source code is released under:

Apache License

Java Source Code

/*
 * Copyright 2009 ZXing authors/*  w  ww.  j  ava2  s  . c  o m*/
 * Copyright 2011 Robert Theis
 *
 * 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 ch.luklanis.esscan;

import android.graphics.Bitmap;

/**
 * This object extends LuminanceSource around an array of YUV data returned from the camera driver,
 * with the option to crop to a rectangle within the full data. This can be used to exclude
 * superfluous pixels around the perimeter and speed up decoding.
 * <p/>
 * It works for any pixel format where the Y channel is planar and appears first, including
 * YCbCr_420_SP and YCbCr_422_SP.
 * <p/>
 * The code for this class was adapted from the ZXing project: http://code.google.com/p/zxing
 */
public final class PlanarYUVLuminanceSource extends LuminanceSource {

    private final byte[] yuvData;
    private final int dataWidth;
    private final int dataHeight;
    private final int left;
    private final int top;

    public PlanarYUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left,
                                    int top, int width, int height, boolean reverseHorizontal) {
        super(width, height);

        if (left + width > dataWidth || top + height > dataHeight) {
            throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
        }

        this.yuvData = yuvData;
        this.dataWidth = dataWidth;
        this.dataHeight = dataHeight;
        this.left = left;
        this.top = top;
        if (reverseHorizontal) {
            reverseHorizontal(width, height);
        }
    }

    @Override
    public byte[] getRow(int y, byte[] row) {
        if (y < 0 || y >= getHeight()) {
            throw new IllegalArgumentException("Requested row is outside the image: " + y);
        }
        int width = getWidth();
        if (row == null || row.length < width) {
            row = new byte[width];
        }
        int offset = (y + top) * dataWidth + left;
        System.arraycopy(yuvData, offset, row, 0, width);
        return row;
    }

    @Override
    public byte[] getMatrix() {
        int width = getWidth();
        int height = getHeight();

        // If the caller asks for the entire underlying image, save the copy and give them the
        // original data. The docs specifically warn that result.length must be ignored.
        if (width == dataWidth && height == dataHeight) {
            return yuvData;
        }

        int area = width * height;
        byte[] matrix = new byte[area];
        int inputOffset = top * dataWidth + left;

        // If the width matches the full width of the underlying data, perform a single copy.
        if (width == dataWidth) {
            System.arraycopy(yuvData, inputOffset, matrix, 0, area);
            return matrix;
        }

        // Otherwise copy one cropped row at a time.
        byte[] yuv = yuvData;
        for (int y = 0; y < height; y++) {
            int outputOffset = y * width;
            System.arraycopy(yuv, inputOffset, matrix, outputOffset, width);
            inputOffset += dataWidth;
        }
        return matrix;
    }

    public Bitmap renderCroppedGreyscaleBitmap() {
        int width = getWidth();
        int height = getHeight();
        int[] pixels = new int[width * height];
        byte[] yuv = yuvData;
        int inputOffset = top * dataWidth + left;

        for (int y = 0; y < height; y++) {
            int outputOffset = y * width;
            for (int x = 0; x < width; x++) {
                int grey = yuv[inputOffset + x] & 0xff;
                pixels[outputOffset + x] = 0xFF000000 | (grey * 0x00010101);
            }
            inputOffset += dataWidth;
        }

        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    private void reverseHorizontal(int width, int height) {
        byte[] yuvData = this.yuvData;
        for (int y = 0, rowStart = top * dataWidth + left; y < height; y++, rowStart += dataWidth) {
            int middle = rowStart + width / 2;
            for (int x1 = rowStart, x2 = rowStart + width - 1; x1 < middle; x1++, x2--) {
                byte temp = yuvData[x1];
                yuvData[x1] = yuvData[x2];
                yuvData[x2] = temp;
            }
        }
    }

}

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