mudhorn/zxing
1
0
Fork 0
mirror of https://github.com/zxing/zxing.git synced 2025-03-05 20:48:51 -08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Issue 520

Browse source 
git-svn-id: https://zxing.googlecode.com/svn/trunk@1545 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
smparkes@smparkes.net 2010-08-17 20:12:10 +00:00
parent d70e368ef0
commit 3f8639c67e
1 changed files with 41 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

57
cpp/core/src/zxing/qrcode/detector/FinderPatternFinder.cpp
View file

@ -31,27 +31,35 @@ namespace qrcode {
using namespace std; using namespace std;
class ClosestToAverageComparator { class FurthestFromAverageComparator {
private: private:
float averageModuleSize_; const float averageModuleSize_;
public: public:
ClosestToAverageComparator() : averageModuleSize_(0.0f) { } FurthestFromAverageComparator(float averageModuleSize) :
averageModuleSize_(averageModuleSize) {
ClosestToAverageComparator(float averageModuleSize) :
averageModuleSize_(averageModuleSize) {
} }
bool operator()(Ref<FinderPattern> a, Ref<FinderPattern> b) { bool operator()(Ref<FinderPattern> a, Ref<FinderPattern> b) {
float dA = abs(a->getEstimatedModuleSize() - averageModuleSize_); float dA = abs(a->getEstimatedModuleSize() - averageModuleSize_);
float dB = abs(b->getEstimatedModuleSize() - averageModuleSize_); float dB = abs(b->getEstimatedModuleSize() - averageModuleSize_);
return dA < dB; return dA > dB;
} }
}; };
class CenterComparator { class CenterComparator {
const float averageModuleSize_;
public: public:
CenterComparator(float averageModuleSize) :
averageModuleSize_(averageModuleSize) {
}
bool operator()(Ref<FinderPattern> a, Ref<FinderPattern> b) { bool operator()(Ref<FinderPattern> a, Ref<FinderPattern> b) {
// N.B.: we want the result in descending order ... // N.B.: we want the result in descending order ...
return a->getCount() > b->getCount(); if (a->getCount() != b->getCount()) {
return a->getCount() > b->getCount();
} else {
float dA = abs(a->getEstimatedModuleSize() - averageModuleSize_);
float dB = abs(b->getEstimatedModuleSize() - averageModuleSize_);
return dA < dB;
}
} }
}; };
@ -311,12 +319,21 @@ vector<Ref<FinderPattern> > FinderPatternFinder::selectBestPatterns() {
if (startSize > 3) { if (startSize > 3) {
// But we can only afford to do so if we have at least 4 possibilities to choose from // But we can only afford to do so if we have at least 4 possibilities to choose from
float totalModuleSize = 0.0f; float totalModuleSize = 0.0f;
float square = 0.0f;
for (size_t i = 0; i < startSize; i++) { for (size_t i = 0; i < startSize; i++) {
totalModuleSize += possibleCenters_[i]->getEstimatedModuleSize(); float size = possibleCenters_[i]->getEstimatedModuleSize();
totalModuleSize += size;
square += size * size;
} }
float average = totalModuleSize / (float) startSize; float average = totalModuleSize / (float) startSize;
float stdDev = (float)sqrt(square / startSize - average * average);
sort(possibleCenters_.begin(), possibleCenters_.end(), FurthestFromAverageComparator(average));
float limit = max(0.2f * average, stdDev);
for (size_t i = 0; i < possibleCenters_.size() && possibleCenters_.size() > 3; i++) { for (size_t i = 0; i < possibleCenters_.size() && possibleCenters_.size() > 3; i++) {
if (abs(possibleCenters_[i]->getEstimatedModuleSize() - average) > 0.2f * average) { if (abs(possibleCenters_[i]->getEstimatedModuleSize() - average) > limit) {
possibleCenters_.erase(possibleCenters_.begin()+i); possibleCenters_.erase(possibleCenters_.begin()+i);
i--; i--;
} }
@ -325,7 +342,13 @@ vector<Ref<FinderPattern> > FinderPatternFinder::selectBestPatterns() {
if (possibleCenters_.size() > 3) { if (possibleCenters_.size() > 3) {
// Throw away all but those first size candidate points we found. // Throw away all but those first size candidate points we found.
sort(possibleCenters_.begin(), possibleCenters_.end(), CenterComparator()); float totalModuleSize = 0.0f;
for (size_t i = 0; i < startSize; i++) {
float size = possibleCenters_[i]->getEstimatedModuleSize();
totalModuleSize += size;
}
float average = totalModuleSize / (float) startSize;
sort(possibleCenters_.begin(), possibleCenters_.end(), CenterComparator(average));
} }
if (possibleCenters_.size() > 3) { if (possibleCenters_.size() > 3) {
@ -464,11 +487,13 @@ Ref<FinderPatternInfo> FinderPatternFinder::find(DecodeHints const& hints) {
} }
} }
} else { } else {
// Advance to next black pixel stateCount[0] = stateCount[2];
do { stateCount[1] = stateCount[3];
j++; stateCount[2] = stateCount[4];
} while (j < maxJ && !image_->get(j, i)); stateCount[3] = 1;
j--; // back up to that last white pixel stateCount[4] = 0;
currentState = 3;
continue;
} }
// Clear state to start looking again // Clear state to start looking again
currentState = 0; currentState = 0;