Requested DeBand filter from AviSynth

[j7n]

Maybe it is possible to implement the freeware DeBand filter, which exists as an AviSynth plugin or module in FFdshow. It is effective against light banding and blocking of 1 to 2 RGB levels, which arises on smooth gradients after JPEG compression or even without it if the gradient is extremely clean. It is possible to use the processor on still images through AviSynth, but the color depth must be reduced to YV12, which largely defeats the purpose, and memory requirements effectively limit the max resolution. It would be great if this filter was adapted to work on full truecolor depth.

Examples of the filter in action:

http://imgur.com/a/Pzhtz

[jazzman]

The filter doesn't seem to have any effect in the second pair of images. In the other two pairs banding seems to be minimal from the start.

If the original algorithm / code is available and legal to use a filter could possibly implemented with Filtermeister (Windows OS only)

[j7n]

I can see banding in the second set of images on my monitor. It is a clean computer-generated gradient without any dithering. I have doubled the contrast to show it better on the blue sky. Optionally, one could use a paint program to mask out the clouds where processing isn't required, but even without this step the filter can give good results.

http://i.imgur.com/XDSw5OX.png

http://i.imgur.com/UCMtNgk.png

I just noticed that the license is GPL, which is unfortunate. I usually don't care about this kind of stuff, so I didn't pay attention.