Gaussian blur is equivalent to an auto key cipher [0] without a key. Each pixel is composed of a couple pixels from the original. With some simple algebra, cros

Gaussian blur is equivalent to an auto key cipher [0] without a key. Each pixel is composed of a couple pixels from the original. With some simple algebra, cross-examining pixels that have values determined by the same origin pixel, you can reverse the operation. [0] http://en.m.wikipedia.org/wiki/Autokey_cipher http://en.m.wikipedia.org/wiki/Autokey_cipher