PImage b;

void setup()
{
size(500,500);  
b = loadImage("1.jpg");
image(b, 0, 0);
}

void draw()
{

for (int x = 0; x < b.width;x++)
{
  
for (int y = 0; y < b.height;y++)
{
color c = get(x, y);
float v1 = red(c) - int(random(5));
float v2 = green(c) - int(random(15));
float v3 = blue(c) - int(random(25));
color c1 = color(v1,v2,v3);
set(x,y,c1); 
}

}

}