(I'm sure this has been asked and answered before, please forgive the redundancy.)

I need to adapt the brightness tracking example sketch to track more than one point (any past a specified threshold).

As I see it, the key issue is here:

for (int y = 0; y < video.height; y++) {
     for (int x = 0; x < video.width; x++) {
       int pixelValue = video.pixels[index];
       float pixelBrightness = brightness(pixelValue);
       if (pixelBrightness > brightestValue) {
         brightestValue = pixelBrightness;
         brightestY = y;
         brightestX = x;
       }
       index++;
}

I'm guessing that instead of getting a single set of x,y values, I'd declare an array, which creates an ellipse (or whatever) at every pixel past the threshold, and then reference any given ellipse with a for() statement like any array element.

If it's easier, I'm content to limit the tracking to, say, the top 5 brightest points, if it means I can just assign a set list of 5 ellipses to the five brightest points.

As this is just rudimentary blob tracking (I'd rather not go through TUIO and touchlib if I can help it), I'm also curious as to how to include/discount blocks of multiple adjacent pixels.

A free beer for the best answerer if you live in my city!