/*
- * 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;
+import com.google.zxing.datamatrix.DataMatrixReader;
+import com.google.zxing.oned.MultiFormatOneDReader;
+import com.google.zxing.pdf417.PDF417Reader;
import com.google.zxing.qrcode.QRCodeReader;
-import com.google.zxing.upc.UPCReader;
import java.util.Hashtable;
+import java.util.Vector;
/**
- * <p>This implementation can detect barcodes in one of several formats within
- * an image, and then decode what it finds. This implementation supports all
- * barcode formats that this library supports.</p>
+ * MultiFormatReader is a convenience class and the main entry point into the library for most uses.
+ * By default it attempts to decode all barcode formats that the library supports. Optionally, you
+ * can provide a hints object to request different behavior, for example only decoding QR codes.
*
- * <p>For now, only delegates to {@link QRCodeReader}.</p>
- *
- * @author srowen@google.com (Sean Owen), dswitkin@google.com (Daniel Switkin)
+ * @author Sean Owen
+ * @author dswitkin@google.com (Daniel Switkin)
*/
public final class MultiFormatReader implements Reader {
- public Result decode(MonochromeBitmapSource image) throws ReaderException {
- return decode(image, null);
+ private Hashtable hints;
+ private Vector readers;
+
+ /**
+ * This version of decode honors the intent of Reader.decode(BinaryBitmap) in that it
+ * passes null as a hint to the decoders. However, that makes it inefficient to call repeatedly.
+ * Use setHints() followed by decodeWithState() for continuous scan applications.
+ *
+ * @param image The pixel data to decode
+ * @return The contents of the image
+ * @throws NotFoundException Any errors which occurred
+ */
+ public Result decode(BinaryBitmap image) throws NotFoundException {
+ setHints(null);
+ return decodeInternal(image);
+ }
+
+ /**
+ * Decode an image using the hints provided. Does not honor existing state.
+ *
+ * @param image The pixel data to decode
+ * @param hints The hints to use, clearing the previous state.
+ * @return The contents of the image
+ * @throws NotFoundException Any errors which occurred
+ */
+ public Result decode(BinaryBitmap image, Hashtable hints) throws NotFoundException {
+ setHints(hints);
+ return decodeInternal(image);
}
- public Result decode(MonochromeBitmapSource image, Hashtable hints)
- throws ReaderException {
- Hashtable possibleFormats = hints == null ? null : (Hashtable) hints.get(DecodeHintType.POSSIBLE_FORMATS);
- boolean tryUPC = false;
- boolean tryQR = false;
-
- if (possibleFormats == null) {
- tryUPC = true;
- tryQR = true;
- } else if (possibleFormats.contains(BarcodeFormat.UPC)) {
- tryUPC = true;
- } else if (possibleFormats.contains(BarcodeFormat.QR_CODE)) {
- tryQR = true;
- } else {
- throw new ReaderException("POSSIBLE_FORMATS specifies no supported types");
+ /**
+ * Decode an image using the state set up by calling setHints() previously. Continuous scan
+ * clients will get a <b>large</b> speed increase by using this instead of decode().
+ *
+ * @param image The pixel data to decode
+ * @return The contents of the image
+ * @throws NotFoundException Any errors which occurred
+ */
+ public Result decodeWithState(BinaryBitmap image) throws NotFoundException {
+ // Make sure to set up the default state so we don't crash
+ if (readers == null) {
+ setHints(null);
}
-
- // UPC is much faster to decode, so try it first.
- if (tryUPC) {
- try {
- return new UPCReader().decode(image, hints);
- } catch (ReaderException e) {
+ return decodeInternal(image);
+ }
+
+ /**
+ * This method adds state to the MultiFormatReader. By setting the hints once, subsequent calls
+ * to decodeWithState(image) can reuse the same set of readers without reallocating memory. This
+ * is important for performance in continuous scan clients.
+ *
+ * @param hints The set of hints to use for subsequent calls to decode(image)
+ */
+ public void setHints(Hashtable hints) {
+ this.hints = hints;
+
+ boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
+ Vector formats = hints == null ? null : (Vector) hints.get(DecodeHintType.POSSIBLE_FORMATS);
+ readers = new Vector();
+ if (formats != null) {
+ boolean addOneDReader =
+ formats.contains(BarcodeFormat.UPC_A) ||
+ formats.contains(BarcodeFormat.UPC_E) ||
+ formats.contains(BarcodeFormat.EAN_13) ||
+ formats.contains(BarcodeFormat.EAN_8) ||
+ //formats.contains(BarcodeFormat.CODABAR) ||
+ formats.contains(BarcodeFormat.CODE_39) ||
+ formats.contains(BarcodeFormat.CODE_93) ||
+ formats.contains(BarcodeFormat.CODE_128) ||
+ formats.contains(BarcodeFormat.ITF) ||
+ formats.contains(BarcodeFormat.RSS14) ||
+ formats.contains(BarcodeFormat.RSS_EXPANDED);
+ // Put 1D readers upfront in "normal" mode
+ if (addOneDReader && !tryHarder) {
+ readers.addElement(new MultiFormatOneDReader(hints));
+ }
+ if (formats.contains(BarcodeFormat.QR_CODE)) {
+ readers.addElement(new QRCodeReader());
+ }
+ if (formats.contains(BarcodeFormat.DATA_MATRIX)) {
+ readers.addElement(new DataMatrixReader());
+ }
+ if (formats.contains(BarcodeFormat.PDF417)) {
+ readers.addElement(new PDF417Reader());
+ }
+ // At end in "try harder" mode
+ if (addOneDReader && tryHarder) {
+ readers.addElement(new MultiFormatOneDReader(hints));
}
}
-
- // Then fall through to QR codes.
- if (tryQR) {
+ if (readers.isEmpty()) {
+ if (!tryHarder) {
+ readers.addElement(new MultiFormatOneDReader(hints));
+ }
+ readers.addElement(new QRCodeReader());
+
+ readers.addElement(new DataMatrixReader());
+
+ // TODO: Enable once PDF417 has passed QA
+ //readers.addElement(new PDF417Reader());
+
+ if (tryHarder) {
+ readers.addElement(new MultiFormatOneDReader(hints));
+ }
+ }
+ }
+
+ public void reset() {
+ int size = readers.size();
+ for (int i = 0; i < size; i++) {
+ Reader reader = (Reader) readers.elementAt(i);
+ reader.reset();
+ }
+ }
+
+ private Result decodeInternal(BinaryBitmap image) throws NotFoundException {
+ int size = readers.size();
+ for (int i = 0; i < size; i++) {
+ Reader reader = (Reader) readers.elementAt(i);
try {
- return new QRCodeReader().decode(image, hints);
- } catch (ReaderException e) {
+ return reader.decode(image, hints);
+ } catch (ReaderException re) {
+ // continue
}
}
-
- throw new ReaderException("Could not locate and decode a barcode in the image");
+
+ throw NotFoundException.getNotFoundInstance();
}
}
projects / zxing.git / blobdiff