Image varification

I want a webpage that you can download folders of 20 images from.

I want each of those images to have 1 or 2 pixels colours inverted.

I want each subsequent download to invert different pixels to the previous downloads.

Would a measly £100 be enough to persuade someone to create such a thing?

#! /usr/bin/env python
import Image

# Rest is left as an exercise to the reader