参考来源：

利用OpenCV生成关于某点的颜色径向均匀渐变图像

// define head function
#ifndef PS_ALGORITHM_H_INCLUDED
#define PS_ALGORITHM_H_INCLUDED#include <iostream>
#include <string>
#include "cv.h"
#include "highgui.h"
#include "cxmat.hpp"
#include "cxcore.hpp"
#include "math.h"using namespace std;
using namespace cv;void Show_Image(Mat&, const string &);#endif // PS_ALGORITHM_H_INCLUDED/*
This program will generate
color gradient mapping*/#include "PS_Algorithm.h"
#include <time.h>using namespace std;
using namespace cv;int main(void)
{Mat Img(600, 800, CV_32FC3);Scalar a(255.0, 255.0, 255.0);Scalar b(0.0, 0.0, 0.0);Img.setTo(a);int width, height;width=Img.cols;height=Img.rows;Point2f origin(0.0, 0.0);Point2f Cen(Img.cols/2.0, Img.rows/2.0);float dis;if (origin.x<=Cen.x && origin.y<=Cen.y){dis=sqrt((width-1-origin.x)*(width-1-origin.x)+(height-1-origin.y)*(height-1-origin.y));}else if (origin.x<=Cen.x && origin.y>Cen.y){dis=sqrt((width-1-origin.x)*(width-1-origin.x)+origin.y*origin.y);}else if (origin.x>Cen.x && origin.y>Cen.y){dis=sqrt(origin.x*origin.x+(origin.y)*(origin.y));}else{dis=sqrt(origin.x*origin.x+(height-1-origin.y)*(height-1-origin.y));}float weightB=(b[0]-a[0])/dis;float weightG=(b[1]-a[1])/dis;float weightR=(b[2]-a[2])/dis;float dis2;for (int i=0; i<Img.rows; i++){for (int j=0; j<Img.cols; j++){dis2=sqrt((i-origin.x)*(i-origin.x)+(j-origin.y)*(j-origin.y));Img.at<Vec3f>(i,j)[0]=Img.at<Vec3f>(i,j)[0]+weightB*dis2;Img.at<Vec3f>(i,j)[1]=Img.at<Vec3f>(i,j)[1]+weightG*dis2;Img.at<Vec3f>(i,j)[2]=Img.at<Vec3f>(i,j)[2]+weightR*dis2;}}Img=Img/255.0;Show_Image(Img, "img");imwrite("Out.jpg", Img*255);waitKey();cout<<"All is well."<<endl;}// define the show image
#include "PS_Algorithm.h"
#include <iostream>
#include <string>using namespace std;
using namespace cv;void Show_Image(Mat& Image, const string& str)
{namedWindow(str.c_str(),CV_WINDOW_AUTOSIZE);imshow(str.c_str(), Image);}