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C++ changes for r2277

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git-svn-id: https://zxing.googlecode.com/svn/trunk@2330 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
smparkes@smparkes.net 2012-06-26 17:41:34 +00:00
parent 67e77e3b88
commit 9a36418805
2 changed files with 49 additions and 37 deletions
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74
cpp/core/src/zxing/common/HybridBinarizer.cpp
View file

@ -27,8 +27,8 @@ using namespace zxing;
namespace { namespace {
const int BLOCK_SIZE_POWER = 3; const int BLOCK_SIZE_POWER = 3;
const int BLOCK_SIZE = 1 << BLOCK_SIZE_POWER; const int BLOCK_SIZE = 1 << BLOCK_SIZE_POWER; // ...0100...00
const int BLOCK_SIZE_MASK = BLOCK_SIZE - 1; const int BLOCK_SIZE_MASK = BLOCK_SIZE - 1; // ...0011...11
const int MINIMUM_DIMENSION = BLOCK_SIZE * 5; const int MINIMUM_DIMENSION = BLOCK_SIZE * 5;
} }
@ -45,20 +45,21 @@ HybridBinarizer::createBinarizer(Ref<LuminanceSource> source) {
return Ref<Binarizer> (new HybridBinarizer(source)); return Ref<Binarizer> (new HybridBinarizer(source));
} }
/**
* Calculates the final BitMatrix once for all requests. This could be called once from the
* constructor instead, but there are some advantages to doing it lazily, such as making
* profiling easier, and not doing heavy lifting when callers don't expect it.
*/
Ref<BitMatrix> HybridBinarizer::getBlackMatrix() { Ref<BitMatrix> HybridBinarizer::getBlackMatrix() {
// Calculates the final BitMatrix once for all requests. This could
// be called once from the constructor instead, but there are some
// advantages to doing it lazily, such as making profiling easier,
// and not doing heavy lifting when callers don't expect it.
if (matrix_) { if (matrix_) {
return matrix_; return matrix_;
} }
LuminanceSource& source = *getLuminanceSource(); LuminanceSource& source = *getLuminanceSource();
if (source.getWidth() >= MINIMUM_DIMENSION && int width = source.getWidth();
source.getHeight() >= MINIMUM_DIMENSION) { int height = source.getHeight();
if (width >= MINIMUM_DIMENSION && height >= MINIMUM_DIMENSION) {
unsigned char* luminances = source.getMatrix(); unsigned char* luminances = source.getMatrix();
int width = source.getWidth();
int height = source.getHeight();
int subWidth = width >> BLOCK_SIZE_POWER; int subWidth = width >> BLOCK_SIZE_POWER;
if ((width & BLOCK_SIZE_MASK) != 0) { if ((width & BLOCK_SIZE_MASK) != 0) {
subWidth++; subWidth++;
@ -93,6 +94,12 @@ Ref<BitMatrix> HybridBinarizer::getBlackMatrix() {
return matrix_; return matrix_;
} }
namespace {
inline int cap(int value, int min, int max) {
return value < min ? min : value > max ? max : value;
}
}
void void
HybridBinarizer::calculateThresholdForBlock(unsigned char* luminances, HybridBinarizer::calculateThresholdForBlock(unsigned char* luminances,
int subWidth, int subWidth,
@ -103,18 +110,18 @@ HybridBinarizer::calculateThresholdForBlock(unsigned char* luminances,
Ref<BitMatrix> const& matrix) { Ref<BitMatrix> const& matrix) {
for (int y = 0; y < subHeight; y++) { for (int y = 0; y < subHeight; y++) {
int yoffset = y << BLOCK_SIZE_POWER; int yoffset = y << BLOCK_SIZE_POWER;
if (yoffset + BLOCK_SIZE >= height) { int maxYOffset = height - BLOCK_SIZE;
yoffset = height - BLOCK_SIZE; if (yoffset > maxYOffset) {
yoffset = maxYOffset;
} }
for (int x = 0; x < subWidth; x++) { for (int x = 0; x < subWidth; x++) {
int xoffset = x << BLOCK_SIZE_POWER; int xoffset = x << BLOCK_SIZE_POWER;
if (xoffset + BLOCK_SIZE >= width) { int maxXOffset = width - BLOCK_SIZE;
xoffset = width - BLOCK_SIZE; if (xoffset > maxXOffset) {
xoffset = maxXOffset;
} }
int left = (x > 1) ? x : 2; int left = cap(x, 2, subWidth - 3);
left = (left < subWidth - 2) ? left : subWidth - 3; int top = cap(y, 2, subHeight - 3);
int top = (y > 1) ? y : 2;
top = (top < subHeight - 2) ? top : subHeight - 3;
int sum = 0; int sum = 0;
for (int z = -2; z <= 2; z++) { for (int z = -2; z <= 2; z++) {
int *blackRow = &blackPoints[(top + z) * subWidth]; int *blackRow = &blackPoints[(top + z) * subWidth];
@ -125,17 +132,17 @@ HybridBinarizer::calculateThresholdForBlock(unsigned char* luminances,
sum += blackRow[left + 2]; sum += blackRow[left + 2];
} }
int average = sum / 25; int average = sum / 25;
threshold8x8Block(luminances, xoffset, yoffset, average, width, matrix); thresholdBlock(luminances, xoffset, yoffset, average, width, matrix);
} }
} }
} }
void HybridBinarizer::threshold8x8Block(unsigned char* luminances, void HybridBinarizer::thresholdBlock(unsigned char* luminances,
int xoffset, int xoffset,
int yoffset, int yoffset,
int threshold, int threshold,
int stride, int stride,
Ref<BitMatrix> const& matrix) { Ref<BitMatrix> const& matrix) {
for (int y = 0, offset = yoffset * stride + xoffset; for (int y = 0, offset = yoffset * stride + xoffset;
y < BLOCK_SIZE; y < BLOCK_SIZE;
y++, offset += stride) { y++, offset += stride) {
@ -157,20 +164,25 @@ namespace {
} }
int* HybridBinarizer::calculateBlackPoints(unsigned char* luminances, int subWidth, int subHeight, int* HybridBinarizer::calculateBlackPoints(unsigned char* luminances,
int width, int height) { int subWidth,
int subHeight,
int width,
int height) {
const int minDynamicRange = 24; const int minDynamicRange = 24;
int *blackPoints = new int[subHeight * subWidth]; int *blackPoints = new int[subHeight * subWidth];
for (int y = 0; y < subHeight; y++) { for (int y = 0; y < subHeight; y++) {
int yoffset = y << BLOCK_SIZE_POWER; int yoffset = y << BLOCK_SIZE_POWER;
if (yoffset + BLOCK_SIZE >= height) { int maxYOffset = height - BLOCK_SIZE;
yoffset = height - BLOCK_SIZE; if (yoffset > maxYOffset) {
yoffset = maxYOffset;
} }
for (int x = 0; x < subWidth; x++) { for (int x = 0; x < subWidth; x++) {
int xoffset = x << BLOCK_SIZE_POWER; int xoffset = x << BLOCK_SIZE_POWER;
if (xoffset + BLOCK_SIZE >= width) { int maxXOffset = width - BLOCK_SIZE;
xoffset = width - BLOCK_SIZE; if (xoffset > maxXOffset) {
xoffset = maxXOffset;
} }
int sum = 0; int sum = 0;
int min = 0xFF; int min = 0xFF;

12
cpp/core/src/zxing/common/HybridBinarizer.h
View file

@ -55,12 +55,12 @@ namespace zxing {
int height, int height,
int blackPoints[], int blackPoints[],
Ref<BitMatrix> const& matrix); Ref<BitMatrix> const& matrix);
void threshold8x8Block(unsigned char* luminances, void thresholdBlock(unsigned char* luminances,
int xoffset, int xoffset,
int yoffset, int yoffset,
int threshold, int threshold,
int stride, int stride,
Ref<BitMatrix> const& matrix); Ref<BitMatrix> const& matrix);
}; };
} }