OpenCV——PS滤镜算法之Spherize 球面化（凸出效果）

// 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


#include "PS_Algorithm.h"
#include <time.h>

using namespace std;
using namespace cv;

#define pi 3.1415926

int main()
{
    string Img_name("4.jpg");
    Mat Img;
    Img=imread(Img_name);

    Mat Img_out(Img.size(), CV_8UC3);
    Img.copyTo(Img_out);

    int width=Img.cols;
    int height=Img.rows;

    float R;
    float e;
    float a,b;
    float alpha=0.75;
    float K=pi/2;

    a=height/2.0; b=width/2.0;
    e=(float)width/(float)height;
    R=std::min(a,b);

    Point Center(width/2, height/2);

    float radius,Dis,new_x, new_y;
    float p,q,x1,y1,x0,y0;
    float theta;

    for (int y=0; y<height; y++)
    {
        for (int x=0; x<width; x++)
        {
            y0=Center.y-y;
            x0=x-Center.x;
            Dis=x0*x0+y0*y0;
            if(Dis<R*R)
            {
                theta=atan(y0/(x0+0.00001));
                if(x0<0) theta=theta+pi;
                radius=asin(sqrt(Dis)/R)*R/K;
                radius=(sqrt(Dis)-radius)*(1-alpha)+radius;
                new_x=radius*cos(theta);
                new_y=radius*sin(theta);
                new_x=Center.x+new_x;
                new_y=Center.y-new_y;

                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;

                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];
                }

            }

        }
    }

    Img_out=Img_out;
    Show_Image(Img_out, "out");

    imwrite("Out.jpg", Img_out);


    waitKey();

}


// 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);

}

原图 

效果图

原文：http://blog.csdn.net/matrix_space/article/details/42392219