This thread was inspired by a thread I replied to in chit chat and I thought I'd start a showcase of the cool things you can do images with a little math.

Assuming that you know how the distortion/blurring was done, it's an almost trivial matter to reverse.

Just a few examples:
http://www.umiacs.umd.edu/~aagrawal/sig06/license.html
http://blogs.mathworks.com/steve/2007/08/13/image-deblurring-introduction/
http://www.dsp.rice.edu/software/ward.shtml

10/10/2007 1:48:51 AM

For those that want the quick summary...



plus

math

yields

10/10/2007 11:46:44 AM

math is for squares

10/10/2007 12:04:33 PM

glassy auras seem to be impervious to math

10/10/2007 1:18:46 PM

SOMEONE DO mytwocents


[Edited on October 10, 2007 at 2:38 PM. Reason : ]

10/10/2007 2:36:31 PM

no one's called dibs yet?

10/10/2007 3:04:49 PM

i'm guessing this was insipred by that pedophile that his face was unscrambled?

10/10/2007 4:13:02 PM

^^^ Pixelation is hard to correct for because it's basically a area color average meaning that the sum data is lost. It's not a per pixel transformation. Something like a Gaussian blur is an per pixel transform where individual pixels are changed based on their neighbors and all of the pixel information remains, just altered and moved around.

10/10/2007 5:52:29 PM

try it anyway

10/10/2007 8:37:49 PM

Quote :

"pseudo-inverse"

brings back memories of my neural networks class

10/10/2007 8:55:19 PM

no one else has some cool image manipulation tricks/scripts?

10/15/2007 1:22:09 PM

Quote :

"SOMEONE DO mytwocents"

who hasn't?


ba dum ching

10/15/2007 2:01:04 PM

Topic online today shows a neat example of image descrambling to identify a criminal -

http://thelede.blogs.nytimes.com/2007/10/15/trail-to-suspected-pedophile-reignited-online/?hp

10/15/2007 6:01:18 PM

^ That's what made me start this discussion.

Note to everyone: If you're going to alter a photo to conceal your identity, don't use a method that leverages a reversible mathemetical function. Follow mytwocents's example and use a non-reversible method.

10/15/2007 6:10:24 PM