def average_color(x, y, w, h, image):
    r, g, b = 0, 0, 0
    count = 0
    for s in range(x, x + w + 1):
        for t in range(y, y + h + 1):
            pixlr, pixlg, pixlb = image[s, t]
            r += pixlr
            g += pixlg
            b += pixlb
            count += 1
    return ((r / count), (g / count), (b / count))

def differences(rgb_tuple1, rgb_tuple2):
    r1, g1, b1 = rgb_tuple1
    r2, g2, b2 = rgb_tuple2

    return ((r1-r2), (g1-g2), (b1-b2))

def threshold(diff_tuple, trigger=4):
    dr, dg, db = diff_tuple
    return (((( dr**4 + dg**4 + db**4 ) / 3)**0.25) > trigger)        # Thanks to Thomas Atkins, math whiz