PS 滤镜——漩涡 vortex

%%% Vortex
%%% 漩涡效果

clc;
clear all;
close all;

addpath('E:\PhotoShop Algortihm\Image Processing\PS Algorithm');

I=imread('4.jpg');
Image=double(I);

[row, col,channel]=size(Image);
R=floor(max(row, col)/2);
Image_new=Image;
Degree=45;
Center_X=(col+1)/2;
Center_Y=(row+1)/2;

for i=1:row
    for j=1:col
        x0=j-Center_X;
        y0=Center_Y-i;
        if(x0~=0)
            beta=atan(y0/x0);
            if(x0<0)
                beta=beta+pi;
            end
        else
            beta=pi/2;
        end
        radius=sqrt(x0*x0+y0*y0);
        beta=beta+radius/Degree;
        x=radius*cos(beta);
        y=radius*sin(beta);
        x=x+col/2;
        y=row/2-y;
        if(x>1 && x<col && y<row && y>1)
            x1=floor(x);
            y1=floor(y);
            p=x-x1;
            q=y-y1;
            Image_new(i,j,:)=(1-p)*(1-q)*Image(y1,x1,:)+p*(1-q)*Image(y1,x1+1,:)...
                +q*(1-p)*Image(y1+1,x1,:)+p*q*Image(y1+1,x1+1,:);
        end
    end
end
figure, imshow(Image_new/255);

原图 

效果图

原文：http://blog.csdn.net/matrix_space/article/details/42215191