PS 滤镜— —Twirl Filter

来源：互联网发布：越南教科书知乎编辑：程序博客网时间：2024/06/07 02:15

    clc;    clear all;    close all;    addpath('E:\PhotoShop Algortihm\Image Processing\PS Algorithm');    I=imread('4.jpg');    I=double(I);    Image=I/255;    [height, width, depth]=size(Image);     angle=pi/2;     centreX = 0.5;     centreY = 0.5;     radius=200;     icentreX=width*centreX;     icentreY=height*centreY;     radius2=radius*radius;     Image_new=Image;     for ii=1:height        for jj=1:width             dx=jj-icentreX;             dy=ii-icentreY;             distance2=dx*dx+dy*dy;             if (distance2>radius2)                 x=jj;                 y=ii;             else                 distance=sqrt(distance2);                 a = atan2(dy, dx) + angle * (radius-distance) / radius;                 x = icentreX + distance*cos(a);                 y = icentreY + distance*sin(a);               end    % %         if (x<=1)     x=1;  end    % %         if (x>=width)   x=width-1; end;    % %         if (y>=height)  y=height-1; end;    % %         if (y<1)  y=1;     end;            if (x<=1)     continue;  end            if (x>=width)   continue; end;            if (y>=height)  continue; end;            if (y<1)  continue;     end;            x1=floor(x);            y1=floor(y);            p=x-x1;            q=y-y1;            Image_new(ii,jj,:)=(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     imshow(Image_new);     imwrite(Image_new, 'out.jpg');

参考来源：http://www.jhlabs.com/index.html

原图：

这里写图片描述

效果图：

这里写图片描述

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