There's something very special hidden in this image. You will definitely know when you find it.
(I know Stack Exchange lossily compresses images but I've checked and no pixels have been altered.)
Finding traces of the secret might not be that hard. The ideal answer will point to the Stack Exchange question that I took data from to help generate this image (and possibly point to another that can help "decode" it).
I can reveal the secret with this 20 line Python program. I've replaced the most telling bits with
from PIL import Image i = Image.open('hidden.png') d = i.load() x, y = ???, ??? while ???: oldX, oldY = x, y if ???: ??? elif ???: ??? elif ???: ??? else: ??? d[oldX, oldY] = (0, 0, 0) for x in range(i.size): for y in range(i.size): if ???: d[x, y] = (255, 255, 255) i.save('revealed.png')