#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <iostream>
////////////////////////////
//获取高斯模板（空间模板）
///////////////////////////
void getGausssianMask(cv::Mat& Mask, cv::Size wsize, double spaceSigma){
Mask.create(wsize, CV_64F);
int h = wsize.height;
int w = wsize.width;
int center_h = (h - 1) / 2;
int center_w = (w - 1) / 2;
double sum = 0.0;
double x, y;
for (int i = 0; i < h; ++i){
y = pow(i - center_h, 2);
double* Maskdate = Mask.ptr<double>(i);
for (int j = 0; j < w; ++j){
x = pow(j - center_w, 2);
double g = exp(-(x + y) / (2 * spaceSigma * spaceSigma));
Maskdate[j] = g;
sum += g;
}
}
}
////////////////////////////
//获取色彩模板（值域模板）
///////////////////////////
void getColorMask(std::vector<double> &colorMask , double colorSigma){
for (int i = 0; i < 256; ++i){
double colordiff = exp(-(i*i) / (2 * colorSigma * colorSigma));
colorMask.push_back(colordiff);
}
}
////////////////////////////
//双边滤波
///////////////////////////
void bilateralfiter(cv::Mat& src, cv::Mat& dst, cv::Size wsize, double spaceSigma, double colorSigma){
cv::Mat spaceMask;
std::vector<double> colorMask;
cv::Mat Mask0 = cv::Mat::zeros(wsize, CV_64F);
cv::Mat Mask1 = cv::Mat::zeros(wsize, CV_64F);
cv::Mat Mask2 = cv::Mat::zeros(wsize, CV_64F);
getGausssianMask(spaceMask, wsize, spaceSigma);//空间模板
getColorMask(colorMask, colorSigma);//值域模板
int hh = (wsize.height - 1) / 2;
int ww = (wsize.width - 1) / 2;
dst.create(src.size(), src.type());
//边界填充
cv::Mat Newsrc;
cv::copyMakeBorder(src, Newsrc, hh, hh, ww, ww, cv::BORDER_REPLICATE);//边界复制;
for (int i = hh; i < src.rows + hh; ++i){
for (int j = ww; j < src.cols + ww; ++j){
double sum[3] = { 0 };
int graydiff[3] = { 0 };
double space_color_sum[3] = { 0.0 };
for (int r = -hh; r <= hh; ++r){
for (int c = -ww; c <= ww; ++c){
if (src.channels() == 1){
int centerPix = Newsrc.at<uchar>(i, j);
int pix = Newsrc.at<uchar>(i + r, j + c);
graydiff[0] = abs(pix - centerPix);
double colorWeight = colorMask[graydiff[0]];
Mask0.at<double>(r + hh, c + ww) = colorWeight * spaceMask.at<double>(r + hh, c + ww);//滤波模板
space_color_sum[0] = space_color_sum[0] + Mask0.at<double>(r + hh, c + ww);
}
else if (src.channels() == 3){
cv::Vec3b centerPix = Newsrc.at<cv::Vec3b>(i, j);
cv::Vec3b bgr = Newsrc.at<cv::Vec3b>(i + r, j + c);
graydiff[0] = abs(bgr[0] - centerPix[0]); graydiff[1] = abs(bgr[1] - centerPix[1]); graydiff[2] = abs(bgr[2] - centerPix[2]);
double colorWeight0 = colorMask[graydiff[0]];
double colorWeight1 = colorMask[graydiff[1]];
double colorWeight2 = colorMask[graydiff[2]];
Mask0.at<double>(r + hh, c + ww) = colorWeight0 * spaceMask.at<double>(r + hh, c + ww);//滤波模板
Mask1.at<double>(r + hh, c + ww) = colorWeight1 * spaceMask.at<double>(r + hh, c + ww);
Mask2.at<double>(r + hh, c + ww) = colorWeight2 * spaceMask.at<double>(r + hh, c + ww);
space_color_sum[0] = space_color_sum[0] + Mask0.at<double>(r + hh, c + ww);
space_color_sum[1] = space_color_sum[1] + Mask1.at<double>(r + hh, c + ww);
space_color_sum[2] = space_color_sum[2] + Mask2.at<double>(r + hh, c + ww);
}
}
}
//滤波模板归一化
if(src.channels() == 1)
Mask0 = Mask0 / space_color_sum[0];
else{
Mask0 = Mask0 / space_color_sum[0];
Mask1 = Mask1 / space_color_sum[1];
Mask2 = Mask2 / space_color_sum[2];
}
for (int r = -hh; r <= hh; ++r){
for (int c = -ww; c <= ww; ++c){
if (src.channels() == 1){
sum[0] = sum[0] + Newsrc.at<uchar>(i + r, j + c) * Mask0.at<double>(r + hh, c + ww); //滤波
}
else if(src.channels() == 3){
cv::Vec3b bgr = Newsrc.at<cv::Vec3b>(i + r, j + c); //滤波
sum[0] = sum[0] + bgr[0] * Mask0.at<double>(r + hh, c + ww);//B
sum[1] = sum[1] + bgr[1] * Mask1.at<double>(r + hh, c + ww);//G
sum[2] = sum[2] + bgr[2] * Mask2.at<double>(r + hh, c + ww);//R
}
}
}
for (int k = 0; k < src.channels(); ++k){
if (sum[k] < 0)
sum[k] = 0;
else if (sum[k]>255)
sum[k] = 255;
}
if (src.channels() == 1)
{
dst.at<uchar>(i - hh, j - ww) = static_cast<uchar>(sum[0]);
}
else if (src.channels() == 3)
{
cv::Vec3b bgr = { static_cast<uchar>(sum[0]), static_cast<uchar>(sum[1]), static_cast<uchar>(sum[2]) };
dst.at<cv::Vec3b>(i - hh, j - ww) = bgr;
}
}
}
}
int main(){
cv::Mat src = cv::imread("I:\\Learning-and-Practice\\2019Change\\Image process algorithm\\Img\\woman1.jpeg");
if (src.empty()){
return -1;
}
cv::Mat dst;
double spaceSigma = 10;
double colorSigma = 30;
bilateralfiter( src, dst, cv::Size(23,23), spaceSigma, colorSigma);
cv::namedWindow("src", CV_WINDOW_NORMAL);
cv::imshow("src", src);
cv::namedWindow("双边滤波",CV_WINDOW_NORMAL);
cv::imshow("双边滤波", dst);
cv::imwrite("I:\\Learning-and-Practice\\2019Change\\Image process algorithm\\Image Filtering\\BilateralFilter\\woman1.jpg", dst);
cv::waitKey(0);
return 0;
}
