Zhang-Suen细化算法实现不按预期工作

Question

我正在尝试使用Zhang-Suen细化算法.我试图用Java实现它.但问题是它发现我的边缘不是一个像素宽度线.我第一次使用这个算法,我不知道我的逻辑有什么问题.

我想要实现的是:

我能够实现的是:

 public void thinStepI(){

     delList.clear();
    neighbor = 0;
    connectivity = 0;

     for(int i=4;i<width-4;i++)
        for(int j=4;j<height-4;j++){
            p = pixelList[i][j];
            if (p == 1){
                p1 = pixelList[i-1][j]; 
                p2 = pixelList[i-1][j+1]; 
                p3 = pixelList[i][j+1]; 
                p4 = pixelList[i+1][j+1]; 
                p5 = pixelList[i+1][j];
                p6 = pixelList[i+1][j-1]; 
                p7 = pixelList[i][j-1]; 
                p8 = pixelList[i-1][j-1];  


                neighbor = p1 + p2 + p3 + p4 + p5 + p6 + p7 + p8;

                if (p1 == 0 && p2 == 1)
                    connectivity ++;
                if (p2 == 0 && p3 == 1)
                    connectivity ++;
                if (p3 == 0 && p4 == 1)
                    connectivity ++;
                if (p4 == 0 && p5 == 1)
                    connectivity ++;
                if (p5 == 0 && p6 == 1)
                    connectivity ++;
                if (p6 == 0 && p7 == 1)
                    connectivity ++;
                if (p7 == 0 && p8 == 1)
                    connectivity ++;
                if (p8 == 0 && p1 == 1)
                    connectivity ++;

                if ( connectivity == 1 && (neighbor >= 2 && neighbor <= 6) &&
                     (p1 * p3 * p5 == 0) && (p3 * p5 * p7 == 0) ){
                    delList.add(i);
                    delList.add(j);
                }



            }      
        }

     int length = delList.size();
     if (length != 0){
        for(int i =0; i < (length - 1); i+=2){
            pixelList[delList.get(i)][delList.get(i+1)] = 0;
            System.out.println("oldu");
        }
        thinStepI();
     }


}

   public void thinStepII(){
    delList.clear();
    neighbor = 0;
    connectivity = 0;

     for(int i=4;i<width-4;i++)
        for(int j=4;j<height-4;j++){
            if (pixelList[i][j] == 1){
                p  = pixelList[i][j]; // ** Origin Pixel ** 
                p1 = pixelList[i-1][j]; 
                p2 = pixelList[i-1][j+1]; 
                p3 = pixelList[i][j+1]; 
                p4 = pixelList[i+1][j+1]; 
                p5 = pixelList[i+1][j];
                p6 = pixelList[i+1][j-1]; 
                p7 = pixelList[i][j-1]; 
                p8 = pixelList[i-1][j-1];                    

                neighbor = p1 + p2 + p3 + p4 + p5 + p6 + p7 + p8;

                if (p1 == 0 && p2 == 1)
                    connectivity ++;
                if (p2 == 0 && p3 == 1)
                    connectivity ++;
                if (p3 == 0 && p4 == 1)
                    connectivity ++;
                if (p4 == 0 && p5 == 1)
                    connectivity ++;
                if (p5 == 0 && p6 == 1)
                    connectivity ++;
                if (p6 == 0 && p7 == 1)
                    connectivity ++;
                if (p7 == 0 && p8 == 1)
                    connectivity ++;
                if (p8 == 0 && p1 == 1)
                    connectivity ++;

                if ( connectivity == 1 && (neighbor >= 2 && neighbor <= 6) &&
                     (p1 * p3 * p7 == 0) && (p1 * p5 * p7 == 0) ){
                    delList.add(i);
                    delList.add(j);
                }



            }     
        }

     int length = delList.size();
     if (length != 0){
        for(int i =0; i < (length - 1); i+=2){
            pixelList[delList.get(i)][delList.get(i+1)] = 0;
            System.out.println("oldu2");
        }
        thinStepII();
     }

}

我的逻辑中的错误在哪里导致我得到错误的结果？

Answer 1

我认为您用于描述 ZS 算法的链接是错误的。删除前景像素的必要条件是其交叉数为1。“交叉数”是按顺时针顺序遍历8个相邻像素时，前景像素变为背景像素的次数。您的链接中的描述似乎缺少这一点。请参阅： http://www.uel.br/pessoal/josealexandre/stuff/thinning/ftp/lam-lee-survey.pdf 进行更好的讨论。