I want to create a lbp histogram in OpenCV for a picture. Is there any change to create a lbp histogram? Hope for Help..
#include "histogram.hpp"
#include <vector>
template <typename _Tp>
void lbp::histogram_(const Mat& src, Mat& hist, int numPatterns) {
hist = Mat::zeros(1, numPatterns, CV_32SC1);
for(int i = 0; i < src.rows; i++) {
for(int j = 0; j < src.cols; j++) {
int bin = src.at<_Tp>(i,j);
hist.at<int>(0,bin) += 1;
}
}
}
template <typename _Tp>
double lbp::chi_square_(const Mat& histogram0, const Mat& histogram1) {
if(histogram0.type() != histogram1.type())
CV_Error(CV_StsBadArg, "Histograms must be of equal type.");
if(histogram0.rows != 1 || histogram0.rows != histogram1.rows || histogram0.cols != histogram1.cols)
CV_Error(CV_StsBadArg, "Histograms must be of equal dimension.");
double result = 0.0;
for(int i=0; i < histogram0.cols; i++) {
double a = histogram0.at<_Tp>(0,i) - histogram1.at<_Tp>(0,i);
double b = histogram0.at<_Tp>(0,i) + histogram1.at<_Tp>(0,i);
if(abs(b) > numeric_limits<double>::epsilon()) {
result+=(a*a)/b;
}
}
return result;
}
void lbp::spatial_histogram(const Mat& src, Mat& hist, int numPatterns, const Size& window, int overlap) {
int width = src.cols;
int height = src.rows;
vector<Mat> histograms;
for(int x=0; x < width - window.width; x+=(window.width-overlap)) {
for(int y=0; y < height-window.height; y+=(window.height-overlap)) {
Mat cell = Mat(src, Rect(x,y,window.width, window.height));
histograms.push_back(histogram(cell, numPatterns));
}
}
hist.create(1, histograms.size()*numPatterns, CV_32SC1);
// i know this is a bit lame now... feel free to make this a bit more efficient...
for(int histIdx=0; histIdx < histograms.size(); histIdx++) {
for(int valIdx = 0; valIdx < numPatterns; valIdx++) {
int y = histIdx*numPatterns+valIdx;
hist.at<int>(0,y) = histograms[histIdx].at<int>(valIdx);
}
}
}
// wrappers
void lbp::histogram(const Mat& src, Mat& hist, int numPatterns) {
switch(src.type()) {
case CV_8SC1: histogram_<char>(src, hist, numPatterns); break;
case CV_8UC1: histogram_<unsigned char>(src, hist, numPatterns); break;
case CV_16SC1: histogram_<short>(src, hist, numPatterns); break;
case CV_16UC1: histogram_<unsigned short>(src, hist, numPatterns); break;
case CV_32SC1: histogram_<int>(src, hist, numPatterns); break;
}
}
double lbp::chi_square(const Mat& histogram0, const Mat& histogram1) {
switch(histogram0.type()) {
case CV_8SC1: return chi_square_<char>(histogram0,histogram1); break;
case CV_8UC1: return chi_square_<unsigned char>(histogram0,histogram1); break;
case CV_16SC1: return chi_square_<short>(histogram0, histogram1); break;
case CV_16UC1: return chi_square_<unsigned short>(histogram0,histogram1); break;
case CV_32SC1: return chi_square_<int>(histogram0,histogram1); break;
}
}
void lbp::spatial_histogram(const Mat& src, Mat& dst, int numPatterns, int gridx, int gridy, int overlap) {
int width = static_cast<int>(floor(src.cols/gridx));
int height = static_cast<int>(floor(src.rows / gridy));
spatial_histogram(src, dst, numPatterns, Size_<int>(width, height), overlap);
}
// Mat return type functions
Mat lbp::histogram(const Mat& src, int numPatterns) {
Mat hist;
histogram(src, hist, numPatterns);
return hist;
}
Mat lbp::spatial_histogram(const Mat& src, int numPatterns, const Size& window, int overlap) {
Mat hist;
spatial_histogram(src, hist, numPatterns, window, overlap);
return hist;
}
Mat lbp::spatial_histogram(const Mat& src, int numPatterns, int gridx, int gridy, int overlap) {
Mat hist;
spatial_histogram(src, hist, numPatterns, gridx, gridy);
return hist;
}
