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Fixed bug in rotation code for BufferedImageMonochromeBitmapSource; fixed "SKIP_N_BARCODES" behavior to ignore barcodes already found.

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git-svn-id: https://zxing.googlecode.com/svn/trunk@297 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
srowen 2008-03-19 17:09:27 +00:00
parent efb0fb9e3b
commit 14a9eb7d20
6 changed files with 62 additions and 36 deletions
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3
android/src/com/google/zxing/client/android/RGBMonochromeBitmapSource.java
View file

@ -19,6 +19,7 @@ package com.google.zxing.client.android;
import android.graphics.Bitmap;
import com.google.zxing.BlackPointEstimationMethod;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.ReaderException;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.BlackPointEstimator;
@ -77,7 +78,7 @@ final class RGBMonochromeBitmapSource implements MonochromeBitmapSource {
return image.width();
}
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) {
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) throws ReaderException {
if (!method.equals(lastMethod) || argument != lastArgument) {
int width = image.width();
int height = image.height();

3
android/src/com/google/zxing/client/android/YUVMonochromeBitmapSource.java
View file

@ -19,6 +19,7 @@ package com.google.zxing.client.android;
import android.graphics.Bitmap;
import com.google.zxing.BlackPointEstimationMethod;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.ReaderException;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.BlackPointEstimator;
@ -79,7 +80,7 @@ final class YUVMonochromeBitmapSource implements MonochromeBitmapSource {
return image.width();
}
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) {
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) throws ReaderException {
if (!method.equals(lastMethod) || argument != lastArgument) {
int width = image.width();
int height = image.height();

14
core/src/com/google/zxing/common/BlackPointEstimator.java
View file

@ -16,6 +16,8 @@
package com.google.zxing.common;
import com.google.zxing.ReaderException;
/**
* <p>Encapsulates logic that estimates the optimal "black point", the luminance value
* which is the best line between "white" and "black" in a grayscale image.</p>
@ -43,8 +45,9 @@ public final class BlackPointEstimator {
* than 0.0; 1.0 is a good "default"
* @return index within argument of bucket corresponding to brightest values which should be
* considered "black"
* @throws ReaderException if "black" and "white" appear to be very close in luminance in the image
*/
public static int estimate(int[] histogram, float biasTowardsWhite) {
public static int estimate(int[] histogram, float biasTowardsWhite) throws ReaderException{
if (Float.isNaN(biasTowardsWhite) || biasTowardsWhite <= 0.0f) {
throw new IllegalArgumentException("Illegal biasTowardsWhite: " + biasTowardsWhite);
@ -83,6 +86,15 @@ public final class BlackPointEstimator {
secondPeak = temp;
}
// Kind of aribtrary; if the two peaks are very close, then we figure there is so little
// dynamic range in the image, that discriminating black and white is too error-prone.
// Decoding the image/line is either pointless, or may in some cases lead to a false positive
// for 1D formats, which are relatively lenient.
// We arbitrarily say "close" is "fewer than 1/8 of the total histogram buckets apart"
if (secondPeak - firstPeak < histogram.length >> 3) {
throw new ReaderException("Too little dynamic range in luminance");
}
// Find a valley between them that is low and closer to the white peak
int bestValley = secondPeak - 1;
int bestValleyScore = -1;

65
core/src/com/google/zxing/oned/AbstractOneDReader.java
View file

@ -82,20 +82,19 @@ public abstract class AbstractOneDReader implements OneDReader {
// the middle. So we'd scan row middle, then middle - rowStep, then middle + rowStep,
// then middle - 2*rowStep, etc.
// rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily decided
// that moving up and down by about 1/16 of the image is pretty good.
// that moving up and down by about 1/16 of the image is pretty good; we try more of the image if
// "trying harder"
int middle = height >> 1;
int rowStep;
if (tryHarder) {
rowStep = 2; // Look at every other line if "trying harder"
} else {
rowStep = Math.max(1, height >> 4);
}
int rowStep = Math.max(1, height >> (tryHarder ? 7 : 4));
int maxLines;
if (tryHarder || barcodesToSkip > 0) {
maxLines = height; // Look at the whole image; looking for more than one barcode
} else {
maxLines = 7;
}
Result lastResult = null;
for (int x = 0; x < maxLines; x++) {
int rowStepsAboveOrBelow = (x + 1) >> 1;
@ -105,34 +104,40 @@ public abstract class AbstractOneDReader implements OneDReader {
break;
}
image.estimateBlackPoint(BlackPointEstimationMethod.ROW_SAMPLING, rowNumber);
try {
image.estimateBlackPoint(BlackPointEstimationMethod.ROW_SAMPLING, rowNumber);
} catch (ReaderException re) {
continue;
}
image.getBlackRow(rowNumber, row, 0, width);
try {
Result result = decodeRow(rowNumber, row, hints);
if (barcodesToSkip > 0) { // See if we should skip and keep looking
barcodesToSkip--;
} else {
return result;
}
} catch (ReaderException re) {
if (tryHarder) {
row.reverse(); // try scanning the row backwards
try {
Result result = decodeRow(rowNumber, row, hints);
if (barcodesToSkip > 0) { // See if we should skip and keep looking
barcodesToSkip--;
} else {
// Found it, but upside-down:
result.putMetadata(ResultMetadataType.ORIENTATION, new Integer(180));
return result;
}
} catch (ReaderException re2) {
// continue
for (int attempt = 0; attempt < 2; attempt++) {
if (attempt == 1) { // trying again?
if (tryHarder) { // only if "trying harder"
row.reverse(); // reverse the row and continue
} else {
break;
}
}
try {
Result result = decodeRow(rowNumber, row, hints);
if (lastResult == null || !lastResult.getText().equals(result.getText())) {
// Found new barcode, not just the last one again
if (barcodesToSkip > 0) { // See if we should skip and keep looking
barcodesToSkip--;
lastResult = result; // Remember what we just saw
} else {
if (attempt == 1) {
// Found it, but upside-down:
result.putMetadata(ResultMetadataType.ORIENTATION, new Integer(180));
}
return result;
}
}
} catch (ReaderException re) {
// continue
}
}
}
throw new ReaderException("No barcode found");

3
javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
View file

@ -18,6 +18,7 @@ package com.google.zxing.client.j2me;
import com.google.zxing.BlackPointEstimationMethod;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.ReaderException;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.BlackPointEstimator;
@ -77,7 +78,7 @@ public final class LCDUIImageMonochromeBitmapSource implements MonochromeBitmapS
return width;
}
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) {
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) throws ReaderException {
if (!method.equals(lastMethod) || argument != lastArgument) {
int[] histogram = new int[LUMINANCE_BUCKETS];
float biasTowardsWhite = 1.0f;

10
javase/src/com/google/zxing/client/j2se/BufferedImageMonochromeBitmapSource.java
View file

@ -18,6 +18,7 @@ package com.google.zxing.client.j2se;
import com.google.zxing.BlackPointEstimationMethod;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.ReaderException;
import com.google.zxing.common.BitArray;
import com.google.zxing.common.BlackPointEstimator;
@ -51,6 +52,10 @@ public final class BufferedImageMonochromeBitmapSource implements MonochromeBitm
lastArgument = 0;
}
public BufferedImage getImage() {
return image;
}
public boolean isBlack(int x, int y) {
return computeRGBLuminance(image.getRGB(x, y)) < blackPoint;
}
@ -78,7 +83,7 @@ public final class BufferedImageMonochromeBitmapSource implements MonochromeBitm
return image.getWidth();
}
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) {
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) throws ReaderException {
if (!method.equals(lastMethod) || argument != lastArgument) {
int width = image.getWidth();
int height = image.getHeight();
@ -120,8 +125,9 @@ public final class BufferedImageMonochromeBitmapSource implements MonochromeBitm
throw new IllegalStateException("Rotate not supported");
}
// 90 degrees counterclockwise:
AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, image.getHeight());
AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, image.getWidth());
BufferedImageOp op = new AffineTransformOp(transform, AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
// Note width/height are flipped since we are rotating 90 degrees:
BufferedImage rotatedImage = new BufferedImage(image.getHeight(), image.getWidth(), image.getType());
op.filter(image, rotatedImage);
return new BufferedImageMonochromeBitmapSource(rotatedImage);