Quote from: kursexpert on April 13, 2018, 08:06:34 PM

You think someone will do this? And what if change colors of the picture?

Why wouldn't someone do it? it takes literally 3 lines of code to get the difference image:
-read image1
-read image2
-result = (image1 - image2) > 20
this will result in a binary image (black/white) for all pixels that have difference higher than 20.

As for changing colors, it's a fine solution, if the color transformation is non-linear, otherwise it'll be possible to revert the image back easily.

Quote from: jhenfelipe on April 13, 2018, 09:17:52 PM

If you're concerned with that delta image thing, then don't share the original image anymore and just give the image with seed words on the exact date of the quest. Since you're sharing the original image on the site which is supposedly for the 26th of April, you need to change it with a totally different image (with seeds already) on the 26th so you will not worry if someone prepared about that pixel change.

Exactly, the delta image is a valid attack this time only because he shared the original image.