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Add MultipleBarcodeReader interface to allow for more implementations

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git-svn-id: https://zxing.googlecode.com/svn/trunk@927 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
srowen 2009-05-03 05:56:51 +00:00
parent 35800f4bca
commit 361f4504a3
3 changed files with 135 additions and 94 deletions
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2
core/src/com/google/zxing/multi/ByQuadrantReader.java
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@ -31,7 +31,7 @@ import java.util.Hashtable;
* (e.g. QR Codes). Instead this scans the four quadrants of the image -- and also the center 'quadrant'
* to cover the case where a barcode is found in the center.
*
* @see MultipleBarcodeReader
* @see GenericMultipleBarcodeReader
*/
public final class ByQuadrantReader implements Reader {

129
core/src/com/google/zxing/multi/GenericMultipleBarcodeReader.java Normal file
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@ -0,0 +1,129 @@
/*
* Copyright 2009 ZXing authors
*
* 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 com.google.zxing.multi;
import com.google.zxing.Reader;
import com.google.zxing.Result;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.ReaderException;
import com.google.zxing.ResultPoint;
import com.google.zxing.CroppedMonochromeBitmapSource;
import java.util.Hashtable;
import java.util.Vector;
/**
* <p>Attempts to locate multiple barcodes in an image by repeatedly decoding portion of the image.
* After one barcode is found, the areas left, above, right and below the barcode's
* {@link com.google.zxing.ResultPoint}s are scanned, recursively.</p>
*
* <p>A caller may want to also employ {@link ByQuadrantReader} when attempting to
* find multiple 2D barcodes, like QR Codes, in an image, where the presence of multiple barcodes might
* prevent detecting any one of them.</p>
*
* <p>That is, instead of passing a {@link Reader} a caller might pass
* <code>new ByQuadrantReader(reader)</code>.</p>
*
* @author Sean Owen
*/
public final class GenericMultipleBarcodeReader implements MultipleBarcodeReader {
private final Reader delegate;
public GenericMultipleBarcodeReader(Reader delegate) {
this.delegate = delegate;
}
public Result[] decodeMultiple(MonochromeBitmapSource image) throws ReaderException {
return decodeMultiple(image, null);
}
public Result[] decodeMultiple(MonochromeBitmapSource image, Hashtable hints) throws ReaderException {
Vector results = new Vector();
doDecodeMultiple(image, hints, results, 0, 0);
if (results.isEmpty()) {
throw ReaderException.getInstance();
}
int numResults = results.size();
Result[] resultArray = new Result[numResults];
for (int i = 0; i < numResults; i++) {
resultArray[i] = (Result) results.elementAt(i);
}
return resultArray;
}
private void doDecodeMultiple(MonochromeBitmapSource image,
Hashtable hints,
Vector results,
int xOffset,
int yOffset) {
Result result;
try {
result = delegate.decode(image, hints);
} catch (ReaderException re) {
return;
}
results.addElement(translateResultPoints(result, xOffset, yOffset));
ResultPoint[] resultPoints = result.getResultPoints();
if (resultPoints == null || resultPoints.length == 0) {
return;
}
int width = image.getWidth();
int height = image.getHeight();
float minX = width;
float minY = height;
float maxX = 0.0f;
float maxY = 0.0f;
for (int i = 0; i < resultPoints.length; i++) {
ResultPoint point = resultPoints[i];
float x = point.getX();
float y = point.getY();
if (x < minX) {
minX = x;
}
if (y < minY) {
minY = y;
}
if (x > maxX) {
maxX = x;
}
if (y > maxY) {
maxY = y;
}
}
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, 0, 0, (int) minX, height),
hints, results, 0, 0);
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, 0, 0, width, (int) minY),
hints, results, 0, 0);
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, (int) maxX, 0, width, height),
hints, results, (int) maxX, 0);
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, 0, (int) maxY, width, height),
hints, results, 0, (int) maxY);
}
private static Result translateResultPoints(Result result, int xOffset, int yOffset) {
ResultPoint[] oldResultPoints = result.getResultPoints();
ResultPoint[] newResultPoints = new ResultPoint[oldResultPoints.length];
for (int i = 0; i < oldResultPoints.length; i++) {
ResultPoint oldPoint = oldResultPoints[i];
newResultPoints[i] = new ResultPoint(oldPoint.getX() + xOffset, oldPoint.getY() + yOffset);
}
return new Result(result.getText(), result.getRawBytes(), newResultPoints, result.getBarcodeFormat());
}
}

98
core/src/com/google/zxing/multi/MultipleBarcodeReader.java
View file

@ -16,110 +16,22 @@
package com.google.zxing.multi;
import com.google.zxing.Reader;
import com.google.zxing.Result;
import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.ReaderException;
import com.google.zxing.ResultPoint;
import com.google.zxing.CroppedMonochromeBitmapSource;
import java.util.Hashtable;
import java.util.Vector;
/**
* <p>Attempts to locate multiple barcodes in an image by repeatedly decoding portion of the image.
* After one barcode is found, the areas left, above, right and below the barcode's
* {@link com.google.zxing.ResultPoint}s are scanned, recursively.</p>
*
* <p>A caller may want to also employ {@link ByQuadrantReader} when attempting to
* find multiple 2D barcodes, like QR Codes, in an image, where the presence of multiple barcodes might
* prevent detecting any one of them.</p>
*
* <p>That is, instead of passing a {@link Reader} a caller might pass
* <code>new ByQuadrantReader(reader)</code>.</p>
* Implementation of this interface attempt to read several barcodes from one image.
*
* @see com.google.zxing.Reader
* @author Sean Owen
*/
public final class MultipleBarcodeReader {
public interface MultipleBarcodeReader {
private final Reader delegate;
Result[] decodeMultiple(MonochromeBitmapSource image) throws ReaderException;
public MultipleBarcodeReader(Reader delegate) {
this.delegate = delegate;
}
public Result[] decodeMultiple(MonochromeBitmapSource image) throws ReaderException {
return decodeMultiple(image, null);
}
public Result[] decodeMultiple(MonochromeBitmapSource image, Hashtable hints) throws ReaderException {
Vector results = new Vector();
doDecodeMultiple(image, hints, results, 0, 0);
if (results.isEmpty()) {
throw ReaderException.getInstance();
}
int numResults = results.size();
Result[] resultArray = new Result[numResults];
for (int i = 0; i < numResults; i++) {
resultArray[i] = (Result) results.elementAt(i);
}
return resultArray;
}
private void doDecodeMultiple(MonochromeBitmapSource image, Hashtable hints, Vector results, int xOffset, int yOffset) {
Result result;
try {
result = delegate.decode(image, hints);
} catch (ReaderException re) {
return;
}
results.addElement(translateResultPoints(result, xOffset, yOffset));
ResultPoint[] resultPoints = result.getResultPoints();
if (resultPoints == null || resultPoints.length == 0) {
return;
}
int width = image.getWidth();
int height = image.getHeight();
float minX = width;
float minY = height;
float maxX = 0.0f;
float maxY = 0.0f;
for (int i = 0; i < resultPoints.length; i++) {
ResultPoint point = resultPoints[i];
float x = point.getX();
float y = point.getY();
if (x < minX) {
minX = x;
}
if (y < minY) {
minY = y;
}
if (x > maxX) {
maxX = x;
}
if (y > maxY) {
maxY = y;
}
}
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, 0, 0, (int) minX, height),
hints, results, 0, 0);
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, 0, 0, width, (int) minY),
hints, results, 0, 0);
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, (int) maxX, 0, width, height),
hints, results, (int) maxX, 0);
doDecodeMultiple(new CroppedMonochromeBitmapSource(image, 0, (int) maxY, width, height),
hints, results, 0, (int) maxY);
}
private static Result translateResultPoints(Result result, int xOffset, int yOffset) {
ResultPoint[] oldResultPoints = result.getResultPoints();
ResultPoint[] newResultPoints = new ResultPoint[oldResultPoints.length];
for (int i = 0; i < oldResultPoints.length; i++) {
ResultPoint oldPoint = oldResultPoints[i];
newResultPoints[i] = new ResultPoint(oldPoint.getX() + xOffset, oldPoint.getY() + yOffset);
}
return new Result(result.getText(), result.getRawBytes(), newResultPoints, result.getBarcodeFormat());
}
Result[] decodeMultiple(MonochromeBitmapSource image, Hashtable hints) throws ReaderException;
}