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Brought this back into sync with BufferedImageMonochromeBitmapSource

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git-svn-id: https://zxing.googlecode.com/svn/trunk@205 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
srowen 2008-02-15 17:51:11 +00:00
parent febdcf8d15
commit 4c4adc953e
1 changed files with 14 additions and 57 deletions
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71
android/src/com/google/zxing/client/android/YUVMonochromeBitmapSource.java
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@ -34,9 +34,6 @@ import com.google.zxing.common.BlackPointEstimator;
final class YUVMonochromeBitmapSource implements MonochromeBitmapSource {
private final Bitmap image;
private final BitArray[] blackWhitePixels;
private final int width;
private final int height;
private int blackPoint;
private BlackPointEstimationMethod lastMethod;
private int lastArgument;
@ -46,108 +43,68 @@ final class YUVMonochromeBitmapSource implements MonochromeBitmapSource {
private static final int LUMINANCE_BUCKETS = 1 << LUMINANCE_BITS;
YUVMonochromeBitmapSource(Bitmap image) {
width = image.width();
height = image.height();
this.image = image;
blackWhitePixels = new BitArray[height];
blackPoint = 0x7F;
lastMethod = null;
lastArgument = 0;
}
public boolean isBlack(int x, int y) {
BitArray blackWhite = blackWhitePixels[y];
if (blackWhite == null) {
blackWhite = parseBlackWhite(y);
}
return blackWhite.get(x);
return ((image.getPixel(x, y) >> 16) & 0xFF) < blackPoint;
}
public BitArray getBlackRow(int y, BitArray row, int startX, int getWidth) {
BitArray blackWhite = blackWhitePixels[y];
if (blackWhite == null) {
blackWhite = parseBlackWhite(y);
}
if (row == null) {
if (startX == 0 && getWidth == width) {
return blackWhite;
}
row = new BitArray(getWidth);
} else {
row.clear();
}
int[] pixelRow = new int[getWidth];
image.getPixels(pixelRow, 0, getWidth, startX, y, getWidth, 1);
for (int i = 0; i < getWidth; i++) {
if (blackWhite.get(startX + i)) {
if (((pixelRow[i] >> 16) & 0xFF) < blackPoint) {
row.set(i);
}
}
return row;
}
private BitArray parseBlackWhite(int y) {
int width = this.width;
int[] pixelRow = new int[width];
image.getPixels(pixelRow, 0, width, 0, y, width, 1);
BitArray luminanceRow = new BitArray(width);
int blackPoint = this.blackPoint;
// Calculate 32 bits at a time to more efficiently set the bit array
int bits = 0;
int bitCount = 0;
for (int j = 0; j < width; j++) {
bits >>>= 1;
// Computation of luminance is inlined here for speed:
if (((pixelRow[j] >> 16) & 0xFF) <= blackPoint) {
bits |= 0x80000000;
}
if (++bitCount == 32) {
luminanceRow.setBulk(j, bits);
bits = 0;
bitCount = 0;
}
}
if (bitCount > 0) {
luminanceRow.setBulk(width, bits >>> (32 - bitCount));
}
blackWhitePixels[y] = luminanceRow;
return luminanceRow;
}
public int getHeight() {
return height;
return image.height();
}
public int getWidth() {
return width;
return image.width();
}
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) {
if (!method.equals(lastMethod) || argument != lastArgument) {
for (int i = 0; i < blackWhitePixels.length; i++) {
blackWhitePixels[i] = null;
}
int width = image.width();
int height = image.height();
int[] histogram = new int[LUMINANCE_BUCKETS];
float biasTowardsWhite = 1.0f;
if (method.equals(BlackPointEstimationMethod.TWO_D_SAMPLING)) {
int minDimension = width < height ? width : height;
int startI = height == minDimension ? 0 : (height - width) >> 1;
int startJ = width == minDimension ? 0 : (width - height) >> 1;
for (int n = 0; n < minDimension; n++) {
int pixel = image.getPixel(startJ + n, startI + n);
// Computation of luminance is inlined here for speed:
histogram[((pixel >> 16) & 0xFF) >> LUMINANCE_SHIFT]++;
}
} else if (method.equals(BlackPointEstimationMethod.ROW_SAMPLING)) {
if (argument < 0 || argument >= height) {
throw new IllegalArgumentException("Row is not within the image: " + argument);
}
int[] yuvArray = new int[width];
image.getPixels(yuvArray, 0, width, 0, argument, width, 1);
biasTowardsWhite = 2.0f;
int[] pixelRow = new int[width];
image.getPixels(pixelRow, 0, width, 0, argument, width, 1);
for (int x = 0; x < width; x++) {
histogram[((yuvArray[x] >> 16) & 0xFF) >> LUMINANCE_SHIFT]++;
histogram[((pixelRow[x] >> 16) & 0xFF) >> LUMINANCE_SHIFT]++;
}
} else {
throw new IllegalArgumentException("Unknown method: " + method);
}
blackPoint = BlackPointEstimator.estimate(histogram, 1.0f) << LUMINANCE_SHIFT;
blackPoint = BlackPointEstimator.estimate(histogram, biasTowardsWhite) << LUMINANCE_SHIFT;
lastMethod = method;
lastArgument = argument;
}