From 2bf5701b4fe0060f283a783ac638f928aa794d66 Mon Sep 17 00:00:00 2001 From: srowen Date: Wed, 14 Jan 2009 10:44:46 +0000 Subject: [PATCH] Separated rectangle detection from decoder for reuse git-svn-id: http://zxing.googlecode.com/svn/trunk@824 59b500cc-1b3d-0410-9834-0bbf25fbcc57 --- .../detector/MonochromeRectangleDetector.java | 212 ++++++++++++++++++ .../zxing/datamatrix/detector/Detector.java | 164 +------------- .../zxing/client/j2se/CommandLineRunner.java | 3 +- 3 files changed, 222 insertions(+), 157 deletions(-) create mode 100644 core/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java diff --git a/core/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java b/core/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java new file mode 100644 index 00000000..f3c70d3b --- /dev/null +++ b/core/src/com/google/zxing/common/detector/MonochromeRectangleDetector.java @@ -0,0 +1,212 @@ +/* + * 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.common.detector; + +import com.google.zxing.MonochromeBitmapSource; +import com.google.zxing.ReaderException; +import com.google.zxing.ResultPoint; +import com.google.zxing.BlackPointEstimationMethod; +import com.google.zxing.common.BitArray; +import com.google.zxing.common.GenericResultPoint; + +/** + *

A somewhat generic detector that looks for a barcode-like rectangular region within an image. + * It looks within a mostly white region of an image for a region of black and white, but mostly black. + * It returns the four corners of the region, as best it can determine.

+ * + * @author Sean Owen + */ +public final class MonochromeRectangleDetector { + + private static final int MAX_MODULES = 32; + + private final MonochromeBitmapSource image; + + public MonochromeRectangleDetector(MonochromeBitmapSource image) { + this.image = image; + } + + /** + *

Detects a rectangular region of black and white -- mostly black -- with a region of mostly + * white, in an image.

+ * + * @return {@link ResultPoint[]} describing the corners of the rectangular region. The first and last points + * are opposed on the diagonal, as are the second and third. The first point will be the topmost point and + * the last, the bottommost. The second point will be leftmost and the third, the rightmost + * @throws ReaderException if no Data Matrix Code can be found + */ + public ResultPoint[] detect() throws ReaderException { + + if (!BlackPointEstimationMethod.TWO_D_SAMPLING.equals(image.getLastEstimationMethod())) { + image.estimateBlackPoint(BlackPointEstimationMethod.TWO_D_SAMPLING, 0); + } + + int height = image.getHeight(); + int width = image.getWidth(); + int halfHeight = height >> 1; + int halfWidth = width >> 1; + int iSkip = Math.max(1, height / (MAX_MODULES << 3)); + int jSkip = Math.max(1, width / (MAX_MODULES << 3)); + + int minI = 0; + int maxI = height; + int minJ = 0; + int maxJ = width; + ResultPoint pointA = findCornerFromCenter(halfHeight, -iSkip, minI, maxI, halfWidth, 0, minJ, maxJ, halfWidth >> 1); + minI = (int) pointA.getY() - 1; + ResultPoint pointB = findCornerFromCenter(halfHeight, 0, minI, maxI, halfWidth, -jSkip, minJ, maxJ, halfHeight >> 1); + minJ = (int) pointB.getX() - 1; + ResultPoint pointC = findCornerFromCenter(halfHeight, 0, minI, maxI, halfWidth, jSkip, minJ, maxJ, halfHeight >> 1); + maxJ = (int) pointC.getX() + 1; + ResultPoint pointD = findCornerFromCenter(halfHeight, iSkip, minI, maxI, halfWidth, 0, minJ, maxJ, halfWidth >> 1); + maxI = (int) pointD.getY() + 1; + // Go try to find point A again with better information -- might have been off at first. + pointA = findCornerFromCenter(halfHeight, -iSkip, minI, maxI, halfWidth, 0, minJ, maxJ, halfWidth >> 2); + + return new ResultPoint[] { pointA, pointB, pointC, pointD }; + } + + /** + * Attempts to locate a corner of the barcode by scanning up, down, left or right from a center + * point which should be within the barcode. + * + * @param centerI center's i componennt (vertical) + * @param di change in i per step. If scanning up this is negative; down, positive; left or right, 0 + * @param minI minimum value of i to search through (meaningless when di == 0) + * @param maxI maximum value of i + * @param centerJ center's j component (horizontal) + * @param dj same as di but change in j per step instead + * @param minJ see minI + * @param maxJ see minJ + * @param maxWhiteRun maximum run of white pixels that can still be considered to be within + * the barcode + * @return a {@link com.google.zxing.ResultPoint} encapsulating the corner that was found + * @throws com.google.zxing.ReaderException if such a point cannot be found + */ + private ResultPoint findCornerFromCenter(int centerI, int di, int minI, int maxI, + int centerJ, int dj, int minJ, int maxJ, + int maxWhiteRun) throws ReaderException { + int[] lastRange = null; + for (int i = centerI, j = centerJ; + i < maxI && i >= minI && j < maxJ && j >= minJ; + i += di, j += dj) { + int[] range; + if (dj == 0) { + // horizontal slices, up and down + range = blackWhiteRange(i, maxWhiteRun, minJ, maxJ, true); + } else { + // vertical slices, left and right + range = blackWhiteRange(j, maxWhiteRun, minI, maxI, false); + } + if (range == null) { + if (lastRange == null) { + throw ReaderException.getInstance(); + } + // lastRange was found + if (dj == 0) { + int lastI = i - di; + if (lastRange[0] < centerJ) { + if (lastRange[1] > centerJ) { + // straddle, choose one or the other based on direction + return new GenericResultPoint(di > 0 ? lastRange[0] : lastRange[1], lastI); + } + return new GenericResultPoint(lastRange[0], lastI); + } else { + return new GenericResultPoint(lastRange[1], lastI); + } + } else { + int lastJ = j - dj; + if (lastRange[0] < centerI) { + if (lastRange[1] > centerI) { + return new GenericResultPoint(lastJ, dj < 0 ? lastRange[0] : lastRange[1]); + } + return new GenericResultPoint(lastJ, lastRange[0]); + } else { + return new GenericResultPoint(lastJ, lastRange[1]); + } + } + } + lastRange = range; + } + throw ReaderException.getInstance(); + } + + /** + * Computes the start and end of a region of pixels, either horizontally or vertically, that could be + * part of a Data Matrix barcode. + * + * @param fixedDimension if scanning horizontally, this is the row (the fixed vertical location) where + * we are scanning. If scanning vertically it's the colummn, the fixed horizontal location + * @param maxWhiteRun largest run of white pixels that can still be considered part of the barcode region + * @param minDim minimum pixel location, horizontally or vertically, to consider + * @param maxDim maximum pixel location, horizontally or vertically, to consider + * @param horizontal if true, we're scanning left-right, instead of up-down + * @return int[] with start and end of found range, or null if no such range is found (e.g. only white was found) + */ + private int[] blackWhiteRange(int fixedDimension, int maxWhiteRun, int minDim, int maxDim, boolean horizontal) { + + int center = (minDim + maxDim) / 2; + + BitArray rowOrColumn = horizontal ? image.getBlackRow(fixedDimension, null, 0, image.getWidth()) + : image.getBlackColumn(fixedDimension, null, 0, image.getHeight()); + + // Scan left/up first + int start = center; + while (start >= minDim) { + if (rowOrColumn.get(start)) { + start--; + } else { + int whiteRunStart = start; + do { + start--; + } while (start >= minDim && !rowOrColumn.get(start)); + int whiteRunSize = whiteRunStart - start; + if (start < minDim || whiteRunSize > maxWhiteRun) { + start = whiteRunStart + 1; // back up + break; + } + } + } + start++; + + // Then try right/down + int end = center; + while (end < maxDim) { + if (rowOrColumn.get(end)) { + end++; + } else { + int whiteRunStart = end; + do { + end++; + } while (end < maxDim && !rowOrColumn.get(end)); + int whiteRunSize = end - whiteRunStart; + if (end >= maxDim || whiteRunSize > maxWhiteRun) { + end = whiteRunStart - 1; + break; + } + } + } + end--; + + if (end > start) { + return new int[] { start, end }; + } else { + return null; + } + } + +} \ No newline at end of file diff --git a/core/src/com/google/zxing/datamatrix/detector/Detector.java b/core/src/com/google/zxing/datamatrix/detector/Detector.java index 644fb790..4e47692a 100644 --- a/core/src/com/google/zxing/datamatrix/detector/Detector.java +++ b/core/src/com/google/zxing/datamatrix/detector/Detector.java @@ -19,14 +19,13 @@ package com.google.zxing.datamatrix.detector; import com.google.zxing.MonochromeBitmapSource; import com.google.zxing.ReaderException; import com.google.zxing.ResultPoint; -import com.google.zxing.BlackPointEstimationMethod; -import com.google.zxing.common.BitArray; import com.google.zxing.common.BitMatrix; import com.google.zxing.common.Collections; import com.google.zxing.common.Comparator; import com.google.zxing.common.DetectorResult; import com.google.zxing.common.GenericResultPoint; import com.google.zxing.common.GridSampler; +import com.google.zxing.common.detector.MonochromeRectangleDetector; import java.util.Enumeration; import java.util.Hashtable; @@ -48,9 +47,11 @@ public final class Detector { { new Integer(0), new Integer(1), new Integer(2), new Integer(3), new Integer(4) }; private final MonochromeBitmapSource image; + private final MonochromeRectangleDetector rectangleDetector; public Detector(MonochromeBitmapSource image) { this.image = image; + rectangleDetector = new MonochromeRectangleDetector(image); } /** @@ -61,31 +62,11 @@ public final class Detector { */ public DetectorResult detect() throws ReaderException { - if (!BlackPointEstimationMethod.TWO_D_SAMPLING.equals(image.getLastEstimationMethod())) { - image.estimateBlackPoint(BlackPointEstimationMethod.TWO_D_SAMPLING, 0); - } - - int height = image.getHeight(); - int width = image.getWidth(); - int halfHeight = height >> 1; - int halfWidth = width >> 1; - int iSkip = Math.max(1, height / (MAX_MODULES << 3)); - int jSkip = Math.max(1, width / (MAX_MODULES << 3)); - - int minI = 0; - int maxI = height; - int minJ = 0; - int maxJ = width; - ResultPoint pointA = findCornerFromCenter(halfHeight, -iSkip, minI, maxI, halfWidth, 0, minJ, maxJ, halfWidth >> 1); - minI = (int) pointA.getY() - 1; - ResultPoint pointB = findCornerFromCenter(halfHeight, 0, minI, maxI, halfWidth, -jSkip, minJ, maxJ, halfHeight >> 1); - minJ = (int) pointB.getX() - 1; - ResultPoint pointC = findCornerFromCenter(halfHeight, 0, minI, maxI, halfWidth, jSkip, minJ, maxJ, halfHeight >> 1); - maxJ = (int) pointC.getX() + 1; - ResultPoint pointD = findCornerFromCenter(halfHeight, iSkip, minI, maxI, halfWidth, 0, minJ, maxJ, halfWidth >> 1); - maxI = (int) pointD.getY() + 1; - // Go try to find point A again with better information -- might have been off at first. - pointA = findCornerFromCenter(halfHeight, -iSkip, minI, maxI, halfWidth, 0, minJ, maxJ, halfWidth >> 2); + ResultPoint[] cornerPoints = rectangleDetector.detect(); + ResultPoint pointA = cornerPoints[0]; + ResultPoint pointB = cornerPoints[1]; + ResultPoint pointC = cornerPoints[2]; + ResultPoint pointD = cornerPoints[3]; // Point A and D are across the diagonal from one another, // as are B and C. Figure out which are the solid black lines @@ -178,71 +159,6 @@ public final class Detector { return new DetectorResult(bits, new ResultPoint[] {pointA, pointB, pointC, pointD}); } - /** - * Attempts to locate a corner of the barcode by scanning up, down, left or right from a center - * point which should be within the barcode. - * - * @param centerI center's i componennt (vertical) - * @param di change in i per step. If scanning up this is negative; down, positive; left or right, 0 - * @param minI minimum value of i to search through (meaningless when di == 0) - * @param maxI maximum value of i - * @param centerJ center's j component (horizontal) - * @param dj same as di but change in j per step instead - * @param minJ see minI - * @param maxJ see minJ - * @param maxWhiteRun maximum run of white pixels that can still be considered to be within - * the barcode - * @return a {@link ResultPoint} encapsulating the corner that was found - * @throws ReaderException if such a point cannot be found - */ - private ResultPoint findCornerFromCenter(int centerI, int di, int minI, int maxI, - int centerJ, int dj, int minJ, int maxJ, - int maxWhiteRun) throws ReaderException { - int[] lastRange = null; - for (int i = centerI, j = centerJ; - i < maxI && i >= minI && j < maxJ && j >= minJ; - i += di, j += dj) { - int[] range; - if (dj == 0) { - // horizontal slices, up and down - range = blackWhiteRange(i, maxWhiteRun, minJ, maxJ, true); - } else { - // vertical slices, left and right - range = blackWhiteRange(j, maxWhiteRun, minI, maxI, false); - } - if (range == null) { - if (lastRange == null) { - throw ReaderException.getInstance(); - } - // lastRange was found - if (dj == 0) { - int lastI = i - di; - if (lastRange[0] < centerJ) { - if (lastRange[1] > centerJ) { - // straddle, choose one or the other based on direction - return new GenericResultPoint(di > 0 ? lastRange[0] : lastRange[1], lastI); - } - return new GenericResultPoint(lastRange[0], lastI); - } else { - return new GenericResultPoint(lastRange[1], lastI); - } - } else { - int lastJ = j - dj; - if (lastRange[0] < centerI) { - if (lastRange[1] > centerI) { - return new GenericResultPoint(lastJ, dj < 0 ? lastRange[0] : lastRange[1]); - } - return new GenericResultPoint(lastJ, lastRange[0]); - } else { - return new GenericResultPoint(lastJ, lastRange[1]); - } - } - } - lastRange = range; - } - throw ReaderException.getInstance(); - } - /** * Increments the Integer associated with a key by one. */ @@ -251,70 +167,6 @@ public final class Detector { table.put(key, value == null ? INTEGERS[1] : INTEGERS[value.intValue() + 1]); } - /** - * Computes the start and end of a region of pixels, either horizontally or vertically, that could be - * part of a Data Matrix barcode. - * - * @param fixedDimension if scanning horizontally, this is the row (the fixed vertical location) where - * we are scanning. If scanning vertically it's the colummn, the fixed horizontal location - * @param maxWhiteRun largest run of white pixels that can still be considered part of the barcode region - * @param minDim minimum pixel location, horizontally or vertically, to consider - * @param maxDim maximum pixel location, horizontally or vertically, to consider - * @param horizontal if true, we're scanning left-right, instead of up-down - * @return int[] with start and end of found range, or null if no such range is found (e.g. only white was found) - */ - private int[] blackWhiteRange(int fixedDimension, int maxWhiteRun, int minDim, int maxDim, boolean horizontal) { - - int center = (minDim + maxDim) / 2; - - BitArray rowOrColumn = horizontal ? image.getBlackRow(fixedDimension, null, 0, image.getWidth()) - : image.getBlackColumn(fixedDimension, null, 0, image.getHeight()); - - // Scan left/up first - int start = center; - while (start >= minDim) { - if (rowOrColumn.get(start)) { - start--; - } else { - int whiteRunStart = start; - do { - start--; - } while (start >= minDim && !rowOrColumn.get(start)); - int whiteRunSize = whiteRunStart - start; - if (start < minDim || whiteRunSize > maxWhiteRun) { - start = whiteRunStart + 1; // back up - break; - } - } - } - start++; - - // Then try right/down - int end = center; - while (end < maxDim) { - if (rowOrColumn.get(end)) { - end++; - } else { - int whiteRunStart = end; - do { - end++; - } while (end < maxDim && !rowOrColumn.get(end)); - int whiteRunSize = end - whiteRunStart; - if (end >= maxDim || whiteRunSize > maxWhiteRun) { - end = whiteRunStart - 1; - break; - } - } - } - end--; - - if (end > start) { - return new int[] { start, end }; - } else { - return null; - } - } - private static BitMatrix sampleGrid(MonochromeBitmapSource image, ResultPoint topLeft, ResultPoint bottomLeft, diff --git a/javase/src/com/google/zxing/client/j2se/CommandLineRunner.java b/javase/src/com/google/zxing/client/j2se/CommandLineRunner.java index 78f76265..235950ed 100644 --- a/javase/src/com/google/zxing/client/j2se/CommandLineRunner.java +++ b/javase/src/com/google/zxing/client/j2se/CommandLineRunner.java @@ -33,6 +33,7 @@ import java.io.IOException; import java.io.OutputStreamWriter; import java.io.Writer; import java.net.URI; +import java.net.URISyntaxException; import java.nio.charset.Charset; import java.util.Hashtable; @@ -72,7 +73,7 @@ public final class CommandLineRunner { } private static void decodeOneArgument(String argument, Hashtable hints, - boolean dumpResults) throws Exception { + boolean dumpResults) throws IOException, URISyntaxException { File inputFile = new File(argument); if (inputFile.exists()) { -- 2.20.1