On 10/29/15, P. van Gaans <w3ird_n...@gmx.net> wrote: > You all know the CSI episodes where they read a license plate by > "enhancing" some super-grainy security footage. Nonsense, right? Well, > maybe not.. If the car was parked. And it seems what I found doesn't > exist yet. (but perhaps I overlooked it) > > If you quickly want to know what I'm on about, take a look at these images: > > http://members.ziggo.nl/sinaasappel/images/1_original.jpg (original) > http://members.ziggo.nl/sinaasappel/images/2_40framewind.jpg (40f WIND) > http://members.ziggo.nl/sinaasappel/images/3_wind_hqdn3d.jpg (comparison > with hqdn3d and pp=tn) > > All have limited jpeg compression, but I can deliver PNG files and an > XCF to experiment for yourself if desired. > > So what is WIND? It's what you see if you forget/fail to do motion > detection. (like I did in the images) Also, Wind Is Not a Denoiser. ;-) > It's a way to increase the exposure time of the camera used to shoot a > movie after it's been shot. For the images, I took a 2-second somewhat > grainy clip of a building with nearly no motion. I output the frames to > PNG and load them as layers in The GIMP. I set the opacity for the > bottom layer to 100. The layer above that 50. (100/2) Above that 33.3. > (100/3) 25, 20, 16.7 and so on. Every image with noise is "wrong", some > too dark and some too light. On average, they are spot-on. The > advantage: improved quality and better compression. > > To make this into a proper useable filter, it would need to do this: > > 1. Deshake/stabilize the image. > 2. Divide image in blocks. (e.g. 8x8 pixels) > 3. Figure out it the average color of an 8x8 block is changing during > the next X frames. If not, it's probably not moving and you can average > the values. If it is or is about to, it should be averaged over fewer > frames or not at all. Any area that is about to move will gradually pick > up noise so it doesn't look too unnatural. > 4. Reshake the image. > > Will I do this myself? Maybe, but don't hold your breath. I'm just > sharing this in case somebody finds it interesting and to make sure > nobody can patent it. (assuming it hasn't been done already)
See atadenoise. > > Best regards, > > P. van Gaans > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
