I'm reading screen output and playing it on an Phidget LED 64 array, which accepts values 0-100.

Is there a more robust way to convert from a color value to an integer? I'm nervous that the R value will not be the actual grayscale value. Is it typical for the number to come out as the inverse? Where can I learn more about color information?

  for (int i = 0; i < pixels.length; i++) {
    int val = pixels[i] >> 16;
    val=256+val;
    val=int(map(val,0,255,0,100));
    lightLED(i,val);
}