/*
- * Copyright 2007 Google Inc.
+ * Copyright 2007 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
package com.google.zxing.qrcode;
+import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
-import com.google.zxing.MonochromeBitmapSource;
import com.google.zxing.Reader;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.ResultPoint;
+import com.google.zxing.ResultMetadataType;
+import com.google.zxing.BinaryBitmap;
import com.google.zxing.common.BitMatrix;
+import com.google.zxing.common.DecoderResult;
+import com.google.zxing.common.DetectorResult;
import com.google.zxing.qrcode.decoder.Decoder;
import com.google.zxing.qrcode.detector.Detector;
-import com.google.zxing.qrcode.detector.DetectorResult;
import java.util.Hashtable;
/**
- * @author srowen@google.com (Sean Owen)
+ * This implementation can detect and decode QR Codes in an image.
+ *
+ * @author Sean Owen
*/
-public final class QRCodeReader implements Reader {
+public class QRCodeReader implements Reader {
+
+ private static final ResultPoint[] NO_POINTS = new ResultPoint[0];
+
+ private final Decoder decoder = new Decoder();
+
+ protected Decoder getDecoder() {
+ return decoder;
+ }
/**
* Locates and decodes a QR code in an image.
* @return a String representing the content encoded by the QR code
* @throws ReaderException if a QR code cannot be found, or cannot be decoded
*/
- public Result decode(MonochromeBitmapSource image) throws ReaderException {
+ public Result decode(BinaryBitmap image) throws ReaderException {
return decode(image, null);
}
- public Result decode(MonochromeBitmapSource image, Hashtable hints)
+ public Result decode(BinaryBitmap image, Hashtable hints)
throws ReaderException {
- String text;
+ DecoderResult decoderResult;
ResultPoint[] points;
if (hints != null && hints.containsKey(DecodeHintType.PURE_BARCODE)) {
- BitMatrix bits = extractPureBits(image);
- text = Decoder.decode(bits);
- points = new ResultPoint[0];
+ BitMatrix bits = extractPureBits(image.getBlackMatrix());
+ decoderResult = decoder.decode(bits, hints);
+ points = NO_POINTS;
} else {
- DetectorResult result = new Detector(image).detect();
- text = Decoder.decode(result.getBits());
- points = result.getPoints();
+ DetectorResult detectorResult = new Detector(image.getBlackMatrix()).detect(hints);
+ decoderResult = decoder.decode(detectorResult.getBits(), hints);
+ points = detectorResult.getPoints();
}
- return new Result(text, points);
+
+ Result result = new Result(decoderResult.getText(), decoderResult.getRawBytes(), points, BarcodeFormat.QR_CODE);
+ if (decoderResult.getByteSegments() != null) {
+ result.putMetadata(ResultMetadataType.BYTE_SEGMENTS, decoderResult.getByteSegments());
+ }
+ if (decoderResult.getECLevel() != null) {
+ result.putMetadata(ResultMetadataType.ERROR_CORRECTION_LEVEL, decoderResult.getECLevel().toString());
+ }
+ return result;
}
- private static BitMatrix extractPureBits(MonochromeBitmapSource image)
- throws ReaderException {
+ public void reset() {
+ // do nothing
+ }
+
+ /**
+ * This method detects a barcode in a "pure" image -- that is, pure monochrome image
+ * which contains only an unrotated, unskewed, image of a barcode, with some white border
+ * around it. This is a specialized method that works exceptionally fast in this special
+ * case.
+ */
+ private static BitMatrix extractPureBits(BitMatrix image) throws ReaderException {
// Now need to determine module size in pixels
- // First, skip white border
+
+ int height = image.getHeight();
+ int width = image.getWidth();
+ int minDimension = Math.min(height, width);
+
+ // First, skip white border by tracking diagonally from the top left down and to the right:
int borderWidth = 0;
- while (!image.isBlack(borderWidth, borderWidth)) {
+ while (borderWidth < minDimension && !image.get(borderWidth, borderWidth)) {
borderWidth++;
}
+ if (borderWidth == minDimension) {
+ throw ReaderException.getInstance();
+ }
+
+ // And then keep tracking across the top-left black module to determine module size
int moduleEnd = borderWidth;
- while (image.isBlack(moduleEnd, moduleEnd)) {
+ while (moduleEnd < minDimension && image.get(moduleEnd, moduleEnd)) {
moduleEnd++;
}
+ if (moduleEnd == minDimension) {
+ throw ReaderException.getInstance();
+ }
+
int moduleSize = moduleEnd - borderWidth;
- int rowEndOfSymbol = image.getWidth() - 1;
- while (!image.isBlack(rowEndOfSymbol, borderWidth)) {
+ // And now find where the rightmost black module on the first row ends
+ int rowEndOfSymbol = width - 1;
+ while (rowEndOfSymbol >= 0 && !image.get(rowEndOfSymbol, borderWidth)) {
rowEndOfSymbol--;
}
+ if (rowEndOfSymbol < 0) {
+ throw ReaderException.getInstance();
+ }
rowEndOfSymbol++;
+ // Make sure width of barcode is a multiple of module size
if ((rowEndOfSymbol - borderWidth) % moduleSize != 0) {
- throw new ReaderException("Bad module size / width: " + moduleSize +
- " / " + (rowEndOfSymbol - borderWidth));
+ throw ReaderException.getInstance();
}
int dimension = (rowEndOfSymbol - borderWidth) / moduleSize;
// little off, this will help recover.
borderWidth += moduleSize >> 1;
+ int sampleDimension = borderWidth + (dimension - 1) * moduleSize;
+ if (sampleDimension >= width || sampleDimension >= height) {
+ throw ReaderException.getInstance();
+ }
+
+ // Now just read off the bits
BitMatrix bits = new BitMatrix(dimension);
for (int i = 0; i < dimension; i++) {
int iOffset = borderWidth + i * moduleSize;
for (int j = 0; j < dimension; j++) {
- if (image.isBlack(borderWidth + j * moduleSize, iOffset)) {
- bits.set(i, j);
+ if (image.get(borderWidth + j * moduleSize, iOffset)) {
+ bits.set(j, i);
}
}
}
projects / zxing.git / blobdiff