Color Transfer between Images code实现

上计算机视觉课老师布置的作业实现论文：Color Transfer between Images

基本思路是：

1.给定srcImg和targetImg

2.将RGB空间转为Lab空间

3.根据论文中公式：

计算每一个像素点

4.将resultImg转回到RGB空间显示

效果图：

  

  

见代码：

 #include <opencv2/opencv.hpp>
 #include <opencv2/core/core.hpp>
 #include <opencv2/imgproc/imgproc.hpp>
 #include <math.h>
 using namespace std;
 using namespace cv;

 class ColorTransfer
 {
 public:
     Mat resultImg;

     ColorTransfer(Mat src, Mat target)
     {
         src.convertTo(srcImg_32F, CV_32FC3,1.0f/.f);//这里切记要类型转换下
         target.convertTo(targetImg_32F, CV_32FC3, 1.0f/255.0f);
         resultImg = srcImg_32F;  //将结果先初始化为源图像

         srcImg_Lab = RGBToLab(srcImg_32F);
         targetImg_Lab = RGBToLab(targetImg_32F);
         srcMeans = computeMeans(srcImg_Lab);
         targetMeans = computeMeans(targetImg_Lab);
         srcVariances = computeVariances(srcImg_Lab, srcMeans);
         targetVariances = computeVariances(targetImg_Lab, targetMeans);
         computeResult();
     }

 private:
     //读入的RGB图像
     Mat srcImg_32F;
     Mat targetImg_32F;
     //转换后的Lab空间图像
     Mat srcImg_Lab;
     Mat targetImg_Lab;
     //计算得到的均值和方差
     Vector<double> srcMeans;
     Vector<double> targetMeans;
     Vector<double> srcVariances;
     Vector<double> targetVariances;

     //RGB转换到Lab空间
     Mat RGBToLab(Mat m)
     {
         Mat_<Vec3f> I = m;
         for(int i=;i<I.rows;++i)
         {
             for(int j=;j<I.cols;++j)
             {
                 double L = 0.3811*I(i,j)[] + 0.5783*I(i,j)[] + 0.0402*I(i,j)[];
                 double M = 0.1967*I(i,j)[] + 0.7244*I(i,j)[] + 0.0782*I(i,j)[];
                 double S = 0.0241*I(i,j)[] + 0.1288*I(i,j)[] + 0.8444*I(i,j)[];
                 if(L == ) L = ;
                 if(M == ) M = ;
                 if(S == ) S = ;
                 L = log(L);
                 M = log(M);
                 S = log(S);

                 I(i,j)[] = (L+M+S) / sqrt(3.0);
                 I(i,j)[] = (L+M-*S) / sqrt(6.0);
                 I(i,j)[] = (L-M) / sqrt(2.0);
             }
         }

         return I;
     }

     //Lab转换到RGB空间
     Mat LabToRGB(Mat m)
     {
         Mat_<Vec3f> I = m;
         for(int i=;i<I.rows;++i)
         for(int j=;j<I.cols;++j)
         {
             double L = I(i,j)[]/sqrt(3.0) + I(i,j)[]/sqrt(6.0) + I(i,j)[]/sqrt(2.0);
             double M = I(i,j)[]/sqrt(3.0) + I(i,j)[]/sqrt(6.0) - I(i,j)[]/sqrt(2.0);
             double S = I(i,j)[]/sqrt(3.0) - *I(i,j)[]/sqrt(6.0);

             L = exp(L);
             M = exp(M);
             S = exp(S);

             I(i,j)[] = 4.4679*L - 3.5873*M + 0.1193*S;
             I(i,j)[] = -1.2186*L + 2.3809*M - 0.1624*S;
             I(i,j)[] = 0.0497*L - 0.2439*M + 1.2045*S;
         }

         return I;
     }

     Vector<double> computeMeans(Mat m)
     {
         double sum[] = {  };
         int pixes = m.cols * m.rows;
         Vector<double> means;
         means.resize();
         Mat_<Vec3f> I = m;

         for(int i=;i<I.rows;++i)
         for(int j=;j<I.cols;++j)
         {
             for(int k = ;k < ;k++)
             {
                 sum[k] += I(i,j)[k];
             }
         }

         for(int i = ;i < ;i++)
         {
             means[i] = sum[i] / pixes;
         }

         return means;
     }

     Vector<double> computeVariances(Mat m, Vector<double> means)
     {
         double sum[] = {  };
         int pixes = m.cols * m.rows;
         Mat_<Vec3f> I = m;
         Vector<double> variances;
         variances.resize();

         for(int i=;i<I.rows;++i)
         for(int j=;j<I.cols;++j)
         {
             for(int chanel = ;chanel < ;chanel++)
             {
                 sum[chanel] += abs(I(i,j)[chanel] - means[chanel]);
             }
         }

         for(int i = ;i < ;i++)
         {
             variances[i] = sqrt(sum[i] / pixes);
         }

         return variances;
     }

     void computeResult()
     {
         Mat_<Vec3f> I = resultImg;
         double dataTemp[] = {  };

         for(int chanel =;chanel < ;chanel++)
         {
             dataTemp[chanel] = targetVariances[chanel] / srcVariances[chanel];
         }

         for(int i=;i<I.rows;++i)
         for(int j=;j<I.cols;++j)
         {
             for(int chanel = ;chanel < ;chanel++)
             {
                 I(i,j)[chanel] = dataTemp[chanel] * (I(i,j)[chanel]-srcMeans[chanel]) + targetMeans[chanel];
             }
         }
         resultImg = LabToRGB(resultImg);
     }
 };

 int main()
 {
     Mat src = imread("11.jpg");
     namedWindow("src");
     imshow("src", src);
     Mat target = imread("12.jpg");
     namedWindow("target");
     imshow("target", target);
     ColorTransfer clt(src,target);
     namedWindow("result");
     imshow("result", clt.resultImg);
     Mat saveImg;
     clt.resultImg.convertTo(saveImg,CV_8U, 255.0, /255.0);//imwrite函数只支持8bit和16bit，前面将图像转为了float，保存前要转换
     imwrite("result.jpg",saveImg);

     waitKey();
     return ;
 }