I read in Microsiervos an interesting article about Every Possible Photograph.

I made a Processing program that generates a random image each time you make a click.

//Globals

int w=800;
int h=600;
  
int block_x = 10;
int block_y = 10;
  
int blocks_x=ceil(w/block_x);
int blocks_y=ceil(h/block_y);

void setup() {  
  size(w, h);
}

void draw() {
  
  if (mousePressed) {
    makeit();
  } 
  
}

void makeit() {
  
  for (int i=0;i<blocks_y;i++) {

    int coord_y=i*block_y;
  
    for (int w=0;w<blocks_x;w++) {
      int coord_x=w*block_x;
      color c1 = color(random(0,255), random(0,255), random(0,255));
      fill(c1);
      rect(coord_x, coord_y, coord_x+block_x, coord_y+block_y);
    }
    
  }

}

Processing Screenshot

What is the possibility of hitting a recognizable image? :-)