Processing玩抠图

突然兴起想玩一下抠图，试着用自带的Example\video来改，花了一个中午做了个小样：

分别是白色为底与黑色为底的效果，代码如下：

 1 import processing.video.*;
 2 int numPixels;
 3 int[] backgroundPixels;
 4 Capture video;
 5 PImage img;
 6
 7 void setup() {
 8   size(640, 480);
 9   video = new Capture(this, width, height);
10   video.start();
11   numPixels = video.width * video.height;
12   backgroundPixels = new int[numPixels];
13   img = new PImage(video.width, video.height);//make a copy of video.
14   frameRate(30);
15 }
16
17 void draw() {
18   if (video.available()) {
19     video.read();
20   }
21   img = video;//use img as a template
22   img.loadPixels();
23   for (int i = 0; i < numPixels; i++) {
24     color currColor = img.pixels[i];
25     color bkgdColor = backgroundPixels[i];
26     int currR = (currColor >> 16) & 0xFF;
27     int currG = (currColor >> 8) & 0xFF;
28     int currB = currColor & 0xFF;
29     int bkgdR = (bkgdColor >> 16) & 0xFF;
30     int bkgdG = (bkgdColor >> 8) & 0xFF;
31     int bkgdB = bkgdColor & 0xFF;
32     int diffR = abs(currR - bkgdR);
33     int diffG = abs(currG - bkgdG);
34     int diffB = abs(currB - bkgdB);
35     int td = 20;//set threshold to 20 pixcels;
36
37     //check each pixel of the frame, set background pixels to white.
38     if (diffR >td||diffG>td||diffB>td) {
39       img.pixels[i] = color(currR, currG, currB);
40     } else {
41       img.pixels[i] = color(255, 255, 255);
42     }
43   }
44   img.updatePixels();
45   //use mouse to adjust the blur effect;
46   fastblur(img,(int)map(mouseX,0,width,1,20));
47   //display image.
48   image(img, 0, 0);
49 }
50
51 void keyPressed() {
52   if (key == ‘ ‘) {
53     arraycopy(img.pixels, backgroundPixels);
54   }
55 } 

 1 void fastblur(PImage img,int radius){
 2
 3   if (radius<1){
 4     return;
 5   }
 6   int w=img.width;
 7   int h=img.height;
 8   int wm=w-1;
 9   int hm=h-1;
10   int wh=w*h;
11   int div=radius+radius+1;
12   int r[]=new int[wh];
13   int g[]=new int[wh];
14   int b[]=new int[wh];
15   int rsum,gsum,bsum,x,y,i,p,p1,p2,yp,yi,yw;
16   int vmin[] = new int[max(w,h)];
17   int vmax[] = new int[max(w,h)];
18   int[] pix=img.pixels;
19   int dv[]=new int[256*div];
20   for (i=0;i<256*div;i++){
21      dv[i]=(i/div);
22   }
23
24   yw=yi=0;
25
26   for (y=0;y<h;y++){
27     rsum=gsum=bsum=0;
28     for(i=-radius;i<=radius;i++){
29       p=pix[yi+min(wm,max(i,0))];
30       rsum+=(p & 0xff0000)>>16;
31       gsum+=(p & 0x00ff00)>>8;
32       bsum+= p & 0x0000ff;
33    }
34     for (x=0;x<w;x++){
35
36       r[yi]=dv[rsum];
37       g[yi]=dv[gsum];
38       b[yi]=dv[bsum];
39
40       if(y==0){
41         vmin[x]=min(x+radius+1,wm);
42         vmax[x]=max(x-radius,0);
43        }
44        p1=pix[yw+vmin[x]];
45        p2=pix[yw+vmax[x]];
46
47       rsum+=((p1 & 0xff0000)-(p2 & 0xff0000))>>16;
48       gsum+=((p1 & 0x00ff00)-(p2 & 0x00ff00))>>8;
49       bsum+= (p1 & 0x0000ff)-(p2 & 0x0000ff);
50       yi++;
51     }
52     yw+=w;
53   }
54
55   for (x=0;x<w;x++){
56     rsum=gsum=bsum=0;
57     yp=-radius*w;
58     for(i=-radius;i<=radius;i++){
59       yi=max(0,yp)+x;
60       rsum+=r[yi];
61       gsum+=g[yi];
62       bsum+=b[yi];
63       yp+=w;
64     }
65     yi=x;
66     for (y=0;y<h;y++){
67       pix[yi]=0xff000000 | (dv[rsum]<<16) | (dv[gsum]<<8) | dv[bsum];
68       if(x==0){
69         vmin[y]=min(y+radius+1,hm)*w;
70         vmax[y]=max(y-radius,0)*w;
71       }
72       p1=x+vmin[y];
73       p2=x+vmax[y];
74
75       rsum+=r[p1]-r[p2];
76       gsum+=g[p1]-g[p2];
77       bsum+=b[p1]-b[p2];
78
79       yi+=w;
80     }
81   }
82 }

代码主要分为2个部分：

1. main

获取摄像头帧video，使用PImage对象img作为缓存帧，通过空格保存对比帧background，使用阀值将对比帧与缓存帧之间相同的部分存为指定颜色（例如：白色、黑色），再显示不同的部分。

2. fastblur

简单高斯模糊，本来是想进行边缘柔化的，结果发现这种方法不行，看来只有另外找了。

Processing玩抠图