From 71ee4dc882b86ac5ca2cb2848158076e434de2dc Mon Sep 17 00:00:00 2001 From: srowen Date: Thu, 12 Aug 2010 20:24:38 +0000 Subject: [PATCH] Issue 508 git-svn-id: http://zxing.googlecode.com/svn/trunk@1523 59b500cc-1b3d-0410-9834-0bbf25fbcc57 --- .../google/zxing/common/HybridBinarizer.java | 39 ++++++++++++++----- cpp/core/src/zxing/common/HybridBinarizer.cpp | 34 +++++++++++++--- cpp/core/src/zxing/common/HybridBinarizer.h | 4 +- 3 files changed, 60 insertions(+), 17 deletions(-) diff --git a/core/src/com/google/zxing/common/HybridBinarizer.java b/core/src/com/google/zxing/common/HybridBinarizer.java index e3eb0a21..e89b06f5 100644 --- a/core/src/com/google/zxing/common/HybridBinarizer.java +++ b/core/src/com/google/zxing/common/HybridBinarizer.java @@ -69,11 +69,17 @@ public final class HybridBinarizer extends GlobalHistogramBinarizer { int width = source.getWidth(); int height = source.getHeight(); int subWidth = width >> 3; + if ((width & 0x07) != 0) { + subWidth++; + } int subHeight = height >> 3; - int[][] blackPoints = calculateBlackPoints(luminances, subWidth, subHeight, width); + if ((height & 0x07) != 0) { + subHeight++; + } + int[][] blackPoints = calculateBlackPoints(luminances, subWidth, subHeight, width, height); matrix = new BitMatrix(width, height); - calculateThresholdForBlock(luminances, subWidth, subHeight, width, blackPoints, matrix); + calculateThresholdForBlock(luminances, subWidth, subHeight, width, height, blackPoints, matrix); } else { // If the image is too small, fall back to the global histogram approach. matrix = super.getBlackMatrix(); @@ -82,13 +88,20 @@ public final class HybridBinarizer extends GlobalHistogramBinarizer { } // For each 8x8 block in the image, calculate the average black point using a 5x5 grid - // of the blocks around it. Also handles the corner cases, but will ignore up to 7 pixels - // on the right edge and 7 pixels at the bottom of the image if the overall dimensions are not - // multiples of eight. In practice, leaving those pixels white does not seem to be a problem. + // of the blocks around it. Also handles the corner cases (fractional blocks are computed based + // on the last 8 pixels in the row/column which are also used in the previous block). private static void calculateThresholdForBlock(byte[] luminances, int subWidth, int subHeight, - int stride, int[][] blackPoints, BitMatrix matrix) { + int width, int height, int[][] blackPoints, BitMatrix matrix) { for (int y = 0; y < subHeight; y++) { + int yoffset = y << 3; + if ((yoffset + 8) >= height) { + yoffset = height - 8; + } for (int x = 0; x < subWidth; x++) { + int xoffset = x << 3; + if ((xoffset + 8) >= width) { + xoffset = width - 8; + } int left = (x > 1) ? x : 2; left = (left < subWidth - 2) ? left : subWidth - 3; int top = (y > 1) ? y : 2; @@ -103,7 +116,7 @@ public final class HybridBinarizer extends GlobalHistogramBinarizer { sum += blackRow[left + 2]; } int average = sum / 25; - threshold8x8Block(luminances, x << 3, y << 3, average, stride, matrix); + threshold8x8Block(luminances, xoffset, yoffset, average, width, matrix); } } } @@ -124,15 +137,23 @@ public final class HybridBinarizer extends GlobalHistogramBinarizer { // Calculates a single black point for each 8x8 block of pixels and saves it away. private static int[][] calculateBlackPoints(byte[] luminances, int subWidth, int subHeight, - int stride) { + int width, int height) { int[][] blackPoints = new int[subHeight][subWidth]; for (int y = 0; y < subHeight; y++) { + int yoffset = y << 3; + if ((yoffset + 8) >= height) { + yoffset = height - 8; + } for (int x = 0; x < subWidth; x++) { + int xoffset = x << 3; + if ((xoffset + 8) >= width) { + xoffset = width - 8; + } int sum = 0; int min = 255; int max = 0; for (int yy = 0; yy < 8; yy++) { - int offset = ((y << 3) + yy) * stride + (x << 3); + int offset = (yoffset + yy) * width + xoffset; for (int xx = 0; xx < 8; xx++) { int pixel = luminances[offset + xx] & 0xff; sum += pixel; diff --git a/cpp/core/src/zxing/common/HybridBinarizer.cpp b/cpp/core/src/zxing/common/HybridBinarizer.cpp index 6cfec7ce..91e9e054 100644 --- a/cpp/core/src/zxing/common/HybridBinarizer.cpp +++ b/cpp/core/src/zxing/common/HybridBinarizer.cpp @@ -56,10 +56,16 @@ void HybridBinarizer::binarizeEntireImage() { int width = source->getWidth(); int height = source->getHeight(); int subWidth = width >> 3; + if (width & 0x07) { + subWidth++; + } int subHeight = height >> 3; - int *blackPoints = calculateBlackPoints(luminances, subWidth, subHeight, width); + if (height & 0x07) { + subHeight++; + } + int *blackPoints = calculateBlackPoints(luminances, subWidth, subHeight, width, height); cached_matrix_.reset(new BitMatrix(width,height)); - calculateThresholdForBlock(luminances, subWidth, subHeight, width, blackPoints, cached_matrix_); + calculateThresholdForBlock(luminances, subWidth, subHeight, width, height, blackPoints, cached_matrix_); delete [] blackPoints; delete [] luminances; } else { @@ -70,9 +76,17 @@ void HybridBinarizer::binarizeEntireImage() { } void HybridBinarizer::calculateThresholdForBlock(unsigned char* luminances, int subWidth, int subHeight, - int stride, int blackPoints[], Ref matrix) { + int width, int height, int blackPoints[], Ref matrix) { for (int y = 0; y < subHeight; y++) { + int yoffset = y << 3; + if (yoffset + 8 >= height) { + yoffset = height - 8; + } for (int x = 0; x < subWidth; x++) { + int xoffset = x << 3; + if (xoffset + 8 >= width) { + xoffset = width - 8; + } int left = (x > 1) ? x : 2; left = (left < subWidth - 2) ? left : subWidth - 3; int top = (y > 1) ? y : 2; @@ -87,7 +101,7 @@ void HybridBinarizer::calculateThresholdForBlock(unsigned char* luminances, int sum += blackRow[left + 2]; } int average = sum / 25; - threshold8x8Block(luminances, x << 3, y << 3, average, stride, matrix); + threshold8x8Block(luminances, xoffset, yoffset, average, width, matrix); } } } @@ -106,15 +120,23 @@ void HybridBinarizer::threshold8x8Block(unsigned char* luminances, int xoffset, } int* HybridBinarizer::calculateBlackPoints(unsigned char* luminances, int subWidth, int subHeight, - int stride) { + int width, int height) { int *blackPoints = new int[subHeight * subWidth]; for (int y = 0; y < subHeight; y++) { + int yoffset = y << 3; + if (yoffset + 8 >= height) { + yoffset = height - 8; + } for (int x = 0; x < subWidth; x++) { + int xoffset = x << 3; + if (xoffset + 8 >= width) { + xoffset = width - 8; + } int sum = 0; int min = 255; int max = 0; for (int yy = 0; yy < 8; yy++) { - int offset = ((y << 3) + yy) * stride + (x << 3); + int offset = (yoffset + yy) * width + xoffset; for (int xx = 0; xx < 8; xx++) { int pixel = luminances[offset + xx] & 0xff; sum += pixel; diff --git a/cpp/core/src/zxing/common/HybridBinarizer.h b/cpp/core/src/zxing/common/HybridBinarizer.h index cac8d5bc..2d7653d6 100644 --- a/cpp/core/src/zxing/common/HybridBinarizer.h +++ b/cpp/core/src/zxing/common/HybridBinarizer.h @@ -43,9 +43,9 @@ namespace zxing { void binarizeEntireImage(); // We'll be using one-D arrays because C++ can't dynamically allocate 2D arrays int* calculateBlackPoints(unsigned char* luminances, int subWidth, int subHeight, - int stride); + int width, int height); void calculateThresholdForBlock(unsigned char* luminances, int subWidth, int subHeight, - int stride, int blackPoints[], Ref matrix); + int width, int height, int blackPoints[], Ref matrix); void threshold8x8Block(unsigned char* luminances, int xoffset, int yoffset, int threshold, int stride, Ref matrix); }; -- 2.20.1