And I don't see any way to apply the effect only to a portion of the image (to the watermark area that is).Īnyway, I'd greatly appreciate a filter which can simply use the exact formula to reverse alpha composition, instead of playing around with multiple filters and masks trying out a lot of different combinations of numbers. Values in its brightness/contrast filter have different ranges: black-norma-white for brightness, 0%-200% for contrast (exact numbers aren't even displayed!). Still, I don't know how to reproduce it in VirtualDub. Okay, I got the result, similar to the one from my app, by playing around with a masked brightness/contrast adjustment layer in PhotoShop (values I used: legacy mode, -40 brightness, +30 contrast couldn't get it without legacy mode, somehow it's contrast adjustment is too limited). Second, I need a way to apply a masked brightness/contrast filter to the image. First, I need exact formula for brightness/contrast to precisely calculate (1–Alpha) coefficient. While it's possible to get (Val1–Val2*Alpha)/(1–Alpha) from subtraction ( Val1*(1–Alpha)–Val2*Alpha) and brightness/contrast (something like Contrast*Value+Brightness I think), I need a few more things. Mask the watermark and composite it on top using brightness and contrast to match. Sorry for possible mistakes in my English, my native language is C++. This method works perfectly in case it's possible to exactly reproduce original watermark. Is there a filter for VirtualDub which can apply alpha blending in reverse order, that is, (Val1–Val2*Alpha)/(1–Alpha) instead of normal Val1*(1–Alpha)+Val2*Alpha?īy the way, if you know a plugin for “reversed” applying of layers for PhotoShop, please tell me. The problem is, my app is for still images, but I need a filter. (I believe it can be done, but I haven't tried it yet.) While not perfect, all I need now is to use DeBlend to repair small edges. I've also tried applying reverse alpha blend using my own application and this reproduction of original watermark (it's white with alpha channel, so you may see only white) and got this result: The plugin came to wrong conclusion that some areas need to be repaired etc. Some frames looked quite good, some looked terrible. I've tried using DeLogo to analyse the whole video with this DeBlend mask, but results were unsatisfactory. There's a huge watermark over the whole screen, but it's transparent (only around 15% opacity) and it's quite easy to reproduce roughly.

Bandicam watermark transparent