I want to see an image through a moving circle. I have it working in two different ways inside the black display windows.
First solution:

1.  PImage a;
   void setup()
   {
     size(800,800);
    a = loadImage("tableau1.jpg");
   }
   void draw()
   {
     background(0); 
    noStroke();
    fill(255);
    ellipse(mouseX,mouseY, 150, 150);
   blend(a,0,0,800,800,0,0,800,800,DARKEST);
   }

Second solution:

1. PImage a;
   void setup() {
     size(800, 800);
     a = loadImage("tableau1.jpg");
   }
   void draw(){
     noStroke();
     fill(0);
   rect(0, 0, 800, 800);
   fill(255);
   ellipse(mouseX, mouseY, 150, 150);
   PImage imask = get();
   a.mask(imask);
   image (a,0,0);
   }

 But when I try to get it inside of a BLACK CIRCLE (which is what I want) I cannot get it!
Any idea on how to do it?
Thanks!