Opencv— — kaleidoscope Filter

// 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/*generate the circle transform*/#include "PS_Algorithm.h"#include <time.h>using namespace std;using namespace cv;#define pi 3.1415926float Triangle(float x);int main(){    string Img_name("4.jpg");    Mat Img;    Img=imread(Img_name);    Mat Img_out(Img.size(), CV_8UC3);    int width=Img.cols;    int height=Img.rows;    float angle = pi/4;    float angle2=pi/4;    float centreX = 0.5;    float centreY = 0.5;    float sides = 10;    float icentreX=width*centreX;    float icentreY=height*centreY;    float radius=150;    float dx,dy,new_x,new_y;    float p,q,x1,y1;    float c, r, theta, temp_theta, radius_c;    for (int y=0; y<height; y++)    {        for (int x=0; x<width; x++)        {             dx=x-icentreX;             dy=y-icentreY;             theta=atan2(dy, dx)-angle-angle2;             r=sqrt(dy*dy+dx*dx);             temp_theta=theta/pi*sides*0.5;             theta=Triangle(temp_theta);             if (radius)             {                c=cos(theta);                radius_c=radius/c;                r=radius_c * Triangle(r/radius_c);             }            theta=theta+angle;            new_x=r * cos(theta)+icentreX;            new_y=r * sin(theta)+icentreY;            if(new_x<0)         new_x=0;            if(new_x>=width-1)  new_x=width-2;            if(new_y<0)         new_y=0;            if(new_y>=height-1) new_y=height-2;          //  if (new_x<0)     continue;          //  if (new_x>=width-1)   continue;          //  if (new_y>=height-1)  continue;          //  if (new_y<0)  continue;            x1=(int)new_x;            y1=(int)new_y;            p=new_x-x1;            q=new_y-y1;            for (int k=0; k<3; k++)            {                Img_out.at<Vec3b>(y, x)[k]=(1-p)*(1-q)*Img.at<Vec3b>(y1, x1)[k]+                                        (p)*(1-q)*Img.at<Vec3b>(y1,x1+1)[k]+                                        (1-p)*(q)*Img.at<Vec3b>(y1+1,x1)[k]+                                        (p)*(q)*Img.at<Vec3b>(y1+1,x1+1)[k];            }        }    }    Show_Image(Img_out, "out");    cout<<"All is well"<<endl;   // imwrite("Out.jpg", Img_out);    waitKey();}float Triangle(float x){    float temp_r=fmod(x, 1.0);    if (temp_r<0.5)    {       return 2*temp_r;    }    else    {       return 2*(1-temp_r);    }}// 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);}

图像效果可以参考：

http://blog.csdn.net/matrix_space/article/details/46789783