/*
 * Demonstration of an oval mask.
 */

size(408, 300);   // original image is 408x300
PImage slu = loadImage("http://business.slu.edu/uploads/2012/11/08/slu-homepage-campus4.jpg");
int w = slu.width;
int h = slu.height;

// create the mask image
PGraphics mask = createGraphics(w, h);
mask.beginDraw();
mask.background(0);
mask.fill(255);
mask.ellipse(0.5*w, 0.5*h, w, h);
mask.endDraw();

// apply the mask to the original image
slu.mask(mask);

// draw masked image over a black background
background(0);
image(slu, 0, 0);