| /* |
| * Copyright 2011 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.maxicode; |
| |
| import com.google.zxing.BarcodeFormat; |
| import com.google.zxing.BinaryBitmap; |
| import com.google.zxing.ChecksumException; |
| import com.google.zxing.DecodeHintType; |
| import com.google.zxing.FormatException; |
| import com.google.zxing.NotFoundException; |
| import com.google.zxing.Reader; |
| import com.google.zxing.Result; |
| import com.google.zxing.ResultMetadataType; |
| import com.google.zxing.ResultPoint; |
| import com.google.zxing.common.BitMatrix; |
| import com.google.zxing.common.DecoderResult; |
| import com.google.zxing.maxicode.decoder.Decoder; |
| |
| import java.util.Map; |
| |
| /** |
| * This implementation can detect and decode a MaxiCode in an image. |
| */ |
| public final class MaxiCodeReader implements Reader { |
| |
| private static final ResultPoint[] NO_POINTS = new ResultPoint[0]; |
| private static final int MATRIX_WIDTH = 30; |
| private static final int MATRIX_HEIGHT = 33; |
| |
| private final Decoder decoder = new Decoder(); |
| |
| /** |
| * Locates and decodes a MaxiCode in an image. |
| * |
| * @return a String representing the content encoded by the MaxiCode |
| * @throws NotFoundException if a MaxiCode cannot be found |
| * @throws FormatException if a MaxiCode cannot be decoded |
| * @throws ChecksumException if error correction fails |
| */ |
| @Override |
| public Result decode(BinaryBitmap image) throws NotFoundException, ChecksumException, FormatException { |
| return decode(image, null); |
| } |
| |
| @Override |
| public Result decode(BinaryBitmap image, Map<DecodeHintType,?> hints) |
| throws NotFoundException, ChecksumException, FormatException { |
| // Note that MaxiCode reader effectively always assumes PURE_BARCODE mode |
| // and can't detect it in an image |
| BitMatrix bits = extractPureBits(image.getBlackMatrix()); |
| DecoderResult decoderResult = decoder.decode(bits, hints); |
| Result result = new Result(decoderResult.getText(), decoderResult.getRawBytes(), NO_POINTS, BarcodeFormat.MAXICODE); |
| |
| String ecLevel = decoderResult.getECLevel(); |
| if (ecLevel != null) { |
| result.putMetadata(ResultMetadataType.ERROR_CORRECTION_LEVEL, ecLevel); |
| } |
| return result; |
| } |
| |
| @Override |
| public void reset() { |
| // do nothing |
| } |
| |
| /** |
| * This method detects a code in a "pure" image -- that is, pure monochrome image |
| * which contains only an unrotated, unskewed, image of a code, with some white border |
| * around it. This is a specialized method that works exceptionally fast in this special |
| * case. |
| * |
| * @see com.google.zxing.datamatrix.DataMatrixReader#extractPureBits(BitMatrix) |
| * @see com.google.zxing.qrcode.QRCodeReader#extractPureBits(BitMatrix) |
| */ |
| private static BitMatrix extractPureBits(BitMatrix image) throws NotFoundException { |
| |
| int[] enclosingRectangle = image.getEnclosingRectangle(); |
| if (enclosingRectangle == null) { |
| throw NotFoundException.getNotFoundInstance(); |
| } |
| |
| int left = enclosingRectangle[0]; |
| int top = enclosingRectangle[1]; |
| int width = enclosingRectangle[2]; |
| int height = enclosingRectangle[3]; |
| |
| // Now just read off the bits |
| BitMatrix bits = new BitMatrix(MATRIX_WIDTH, MATRIX_HEIGHT); |
| for (int y = 0; y < MATRIX_HEIGHT; y++) { |
| int iy = top + (y * height + height / 2) / MATRIX_HEIGHT; |
| for (int x = 0; x < MATRIX_WIDTH; x++) { |
| int ix = left + (x * width + width / 2 + (y & 0x01) * width / 2) / MATRIX_WIDTH; |
| if (image.get(ix, iy)) { |
| bits.set(x, y); |
| } |
| } |
| } |
| return bits; |
| } |
| |
| } |