I am working on a sketch that loads around 100 images (640x480) and processes them. I am studying the following example I found on openprocessing.com (sorry can't remember the name of the owner). However, I've noticed performance issues when loading more than 50 images. Can someone have a look and tell me if you can see where the mistake is?

Thanks

2. int IMGHEIGHT;
3. int IMGWIDTH;
4. int CANVASHEIGHT;
5. int CANVASWIDTH;
6. Image[] j = new Image[50];
7. 
   
8. void setup()
9. {
10.   IMGHEIGHT=600;
11.   IMGWIDTH=800;
12.   CANVASHEIGHT=600;
13.   CANVASWIDTH=800;
14.   size(CANVASWIDTH,CANVASHEIGHT);
15.   frameRate(12);
16.   background(0,0,0);
17.  }
18. void draw()
19. {
20.  float freq;
21.  float amp;
22.  float pan;
23.     for(int i=0;i<j.length;i++){
24.       if(j[i] != null){
25.             if( j[i].draw()){
26.               j[i]=null;
27.             }
28.       }
29.       else{
30.           j[i]=new Image(CANVASHEIGHT,CANVASWIDTH,IMGHEIGHT,IMGWIDTH);
31.       }
32.     }
33.  }
34.  
35. class Image{
36.     
37.   int N=50;
38.   PImage i1;
39.  
40.   int x;
41.   int y;
42.   int o;
43.   int r;
44.   int g;
45.   int b;
46.   int h;
47.   int w;
48.   int dx;
49.   int dy;
50.   float ds;
51.   float dt;
52.   int ch;
53.   int cw;
54.    
55.   public Image(int acHeight, int acWidth,int aiHeight, int aiWidth){
56.           
57.     String f=str(int(random(N))+1);
58.     float rd;
59.     rd=random(.3,.7);
60.  
61.     i1=loadImage("Image_"+f+".jpg");
62.       
63.     h=int(rd*aiHeight);
64.     w=int(rd*aiWidth);
65.     x=int(random(acWidth));
66.      
67.     y=int(random(acHeight));
68.     cw=acWidth;
69.     ch=acHeight;
70.     o=int(random(10,20));
71.  
72.     r=int(random(0,255));
73.     g=int(random(0,255));
74.     b=int(random(0,255));
75.     
76.     dx=int(random(-1,2));
77.     dy=int(random(-1,2));
78.     ds=random(.99,1.01);
79.     dt=random(.99, 1.01);
80.   }
81.    
82.   public boolean draw(){
83.   boolean done;
84.   done=false;
85. if (random(100)>60){
86.   x=x+dx;
87.   y=y+dy;
88. }
89.   h=int(h*ds);
90.   w=int(w*ds);
91.   o=int(o*dt);
92.   tint(r,g,b,o);
93.   image(i1,x,y,w,h); 
94.   if(random(20)>17){
95.     dx=int(random(-1,2));
96.     dy=int(random(-1,2));
97.     ds=random(.95,1.05);
98.   }
99.   if (random(100)>96){
100.     done=true;
101.   }
102.     return done;
103.   }
104. }