論文：《基於強邊緣寬度直方圖的圖像清晰度指標.pdf》
實現：
#include <opencv2/opencv.hpp>
#include <opencv2/imgproc.hpp>
#define mydebug
#define test
using namespace cv;
namespace ImageUtil {
float getImageQuality_patchbased(cv::Mat& m,int patchsize,int overlap){
}
float getImageQuality(cv::Mat& m)
{
int nr=m.rows;
int nc=m.cols;
Mat g_x(nr,nc,CV_32FC1);//垂直邊緣圖
Mat g_y(nr,nc,CV_32FC1);//水平邊緣圖
float thresh_x=0.0f;
float thresh_y=0.0f;
#ifdef test
float metric=0.0;
#endif
for(int i=1;i!=nr-1;i++)
{
const uchar* up_line=m.ptr<uchar>(i-1);
const uchar* mid_line=m.ptr<uchar>(i);
const uchar* down_line=m.ptr<uchar>(i+1);
float* cur_x_line=g_x.ptr<float>(i);
float* cur_y_line=g_y.ptr<float>(i);
for(int j=1;j!=nc-1;j++)
{
cur_x_line[j]=(up_line[j-1]-up_line[j+1])+
(mid_line[j-1]-mid_line[j+1])*2+
(down_line[j-1]-down_line[j+1]);
cur_y_line[j]=(up_line[j-1]-down_line[j-1])+
(up_line[j]-down_line[j])*2+
(up_line[j+1]-down_line[j+1]);
thresh_x+=cur_x_line[j]*cur_x_line[j];
thresh_y+=cur_y_line[j]*cur_y_line[j];
#ifdef test
metric+=std::abs(cur_x_line[j]*cur_x_line[j])+std::abs(cur_y_line[j]*cur_y_line[j]);
#endif
}
}
g_x.row(0).setTo(cv::Scalar(0.0f));
g_x.row(nr-1).setTo(cv::Scalar(0.0f));
g_x.col(0).setTo(cv::Scalar(0.0f));
g_x.col(nc-1).setTo(cv::Scalar(0.0f));
g_y.row(0).setTo(cv::Scalar(0.0f));
g_y.row(nr-1).setTo(cv::Scalar(0.0f));
g_y.col(0).setTo(cv::Scalar(0.0f));
g_y.col(nc-1).setTo(cv::Scalar(0.0f));
thresh_x=4*thresh_x/nr/nc;
thresh_y=4*thresh_y/nr/nc;
#ifdef mydebug
//std::cout<<"g_x:"<<std::endl<<g_x<<std::endl;
//std::cout<<"g_y:"<<std::endl<<g_y<<std::endl;
Mat temp_x,temp_y;
g_x.convertTo(temp_x,CV_8UC1);
g_y.convertTo(temp_y,CV_8UC1);
cv::imshow("水平梯度圖",temp_x);
cv::imshow("垂直直方圖",temp_y);
Mat b_x=Mat::zeros(nr,nc,CV_8UC1);
Mat b_y=Mat::zeros(nr,nc,CV_8UC1);
#endif
#ifdef test
std::cout<<"test metricd:"<<metric/nr/nc<<std::endl;
return metric/nr/nc;
#endif
int e_hist_x[nr];//水平邊緣寬度直方圖
int e_hist_y[nc];//垂直邊緣寬度直方圖
for(int i=0;i<nr;i++) e_hist_x[i]=0.0f;
for(int i=0;i<nc;i++) e_hist_y[i]=0.0f;
int nw_x=0;
int nw_y=0;
for(int i=1;i!=nr-1;i++){
float* cur_x_line=g_x.ptr<float>(i);
float* cur_y_line=g_y.ptr<float>(i);
for(int j=1;j!=nc-1;j++){
if(cur_x_line[j]*cur_x_line[j]>thresh_x){//計算垂直方向邊緣寬度
#ifdef mydebug
b_x.ptr<uchar>(i)[j]=255;
#endif
float up=g_x.ptr<float>(i-1)[j];
float down=g_x.ptr<float>(i+1)[j];
float cur=g_x.ptr<float>(i)[j];
int w_x_u=1;
int w_x_d=1;
if(up>=cur && cur>=down){//如果是遞減邊緣
float t_up=up;
float t_cur_up=cur;
while(t_up>t_cur_up && i>w_x_u)
{
w_x_u++;
t_cur_up=t_up;
t_up=g_x.ptr<float>(i-w_x_u)[j];
}
w_x_u--;
float t_down=down;
float t_cur_down=cur;
while(t_down<t_cur_down && i<nr-w_x_d){
w_x_d++;
t_cur_down=t_down;
t_down=g_x.ptr<float>(i+w_x_d)[j];
}
w_x_d--;
}
else if(up<=cur && cur<=down){//如果是遞增邊緣
float t_up=up;
float t_cur_up=cur;
while(t_up<t_cur_up && i>w_x_u){
w_x_u++;
t_cur_up=t_up;
t_up=g_x.ptr<float>(i-w_x_u)[j];
}
w_x_u--;
float t_down=down;
float t_cur_down=cur;
while(t_down>t_cur_down && i<nr-w_x_d){
w_x_d++;
t_cur_down=t_down;
t_down=g_x.ptr<float>(i+w_x_d)[j];
}
w_x_d--;
}
e_hist_x[w_x_d+w_x_u]++;
nw_x++;
}
if(cur_y_line[j]*cur_y_line[j]>thresh_y){//計算水平方向邊緣寬度
#ifdef mydebug
b_y.ptr<uchar>(i)[j]=255;
#endif
float left=cur_y_line[j-1];
float right=cur_y_line[j+1];
float cur=cur_y_line[j];
int w_y_l=1;
int w_y_r=1;
if(left>=cur && cur>=right){//如果是遞減邊緣
float t_left=left;
float t_cur_left=cur;
while(t_left>t_cur_left && j>w_y_l)
{
w_y_l++;
t_cur_left=t_left;
t_left=cur_y_line[j-w_y_l];
}
w_y_l--;
float t_right=right;
float t_cur_right=cur;
while(t_right<t_cur_right && j<nc-w_y_r){
w_y_r++;
t_cur_right=t_right;
t_right=cur_y_line[j+w_y_r];
}
w_y_r--;
}
else if(left<=cur && cur<=right){//如果是遞增邊緣
float t_left=left;
float t_cur_left=cur;
while(t_left<t_cur_left && j>w_y_l){
w_y_l++;
t_cur_left=t_left;
t_left=cur_y_line[j-w_y_l];
}
w_y_l--;
float t_right=right;
float t_cur_right=cur;
while(t_right>t_cur_right && j<nc-w_y_r){
w_y_r++;
t_cur_right=t_right;
t_right=cur_y_line[j+w_y_r];
}
w_y_r--;
}
e_hist_y[w_y_l+w_y_r]++;
nw_y++;
}
}
}
#ifdef mydebug
//std::cout<<"b_x"<<std::endl<<b_x<<std::endl;
//std::cout<<"b_y"<<std::endl<<b_y<<std::endl;
imshow("b_x",b_x);
imshow("b_y",b_y);
std::cout<<"e_hist_x:";
for(int i=0;i<nr;i++)
{
std::cout<<e_hist_x[i]<<",";
}
std::cout<<std::endl;
std::cout<<"e_hist_y:";
for(int i=0;i<nc;i++){
std::cout<<e_hist_y[i]<<",";
}
std::cout<<std::endl;
#endif
//計算x方向清晰度評價值
int wm_x=0,we_x=0;
float maxEdge_x=0.0f;
for(int i=0;i<nr;i++){
if(e_hist_x[i]>maxEdge_x){
maxEdge_x=e_hist_x[i];
wm_x=i;
}
if(e_hist_x[i]!=0) we_x=i;
}
float metric_x=0.0f;
for(int i=0;i!=we_x;i++){
float d=1.0f;
if(i<wm_x) d=(i*i*1.0f)/(wm_x*wm_x);
else if(i==wm_x) d=1;
else d=((we_x-i)*(we_x-i)*1.0f)/((we_x-wm_x)*(we_x-wm_x));
float p=e_hist_x[i]*1.0f/nw_x;
metric_x+=d*p*(i);
}
#ifdef mydebug
#endif
//計算y方向清晰度評價值
int wm_y=0,we_y=0;
float mayEdge_y=0.0f;
for(int i=0;i<nc;i++){
if(e_hist_y[i]>mayEdge_y){
mayEdge_y=e_hist_y[i];
wm_y=i;
}
if(e_hist_y[i]!=0) we_y=i;
}
float metric_y=0.0f;
for(int i=0;i!=we_y;i++){
float d=1.0f;
if(i<wm_y) d=(i*i*1.0f)/(wm_y*wm_y);
else if(i==wm_y) d=1;
else d=((we_y-i)*(we_y-i)*1.0f)/((we_y-wm_y)*(we_y-wm_y));
float p=e_hist_y[i]*1.0f/nw_y;
metric_y+=d*p*(i);
}
#ifdef mydebug
std::cout<<"metric_x:"<<metric_x<<std::endl;
std::cout<<"metric_y:"<<metric_y<<std::endl;
std::cout<<"metric:"<<(metric_x+metric_y)/2<<std::endl;
#endif
return (metric_x+metric_y)/2;
}
}
