= bright and dark

[beetlespin]

i have a video where parts of the movie are just to bright. i have tried basic filters like brighten, darken, gamma correction. the only problem is when you darken the bright areas the rest of the movie is just too dark. the same goes for the dark areas.

i read a thread about how this is done but the software being used is avisynth. i am not familiar with this at all. is there a filter or program that can balance out these areas. i know it's not going to be perfect.

i have seen this question asked, but i the answer was not really what i was looking for. i have searched the forums and i may have missed what i was looking for, if so, sorry for posting and please show me the correct thread.

[AlanHK]

i have a video where parts of the movie are just to bright. i have tried basic filters like brighten, darken, gamma correction.

You need to specify what application you are using.

Maybe 1) Reduce Brightness then
2) increase Gamma.

[beetlespin]

i am using virtualdub, but any advice on a program that might accomplish this task will be great also.

[jagabo]

In VirtualDub first use the Brightness/Contrast filter first to bring the Contrast down 1 or 2 notches. This is important to retain bright details over Y=235. Then use the Levels filter to further adjust the levels and gamma. Use the Preview option and you'll see exactly what's going on.

It can be done better in AviSynth but it's a little more work.

[beetlespin]

i have use the "levels" filter before with good results, but maybe this video is TOO bright. I have 2 snapshots taken with VLC. all the setting in vlc are at their default levels.

[jagabo]

That's probably too far gone. But did you try the brightness trick I gave in the earlier post? That is important because VirtualDub converts incoming YV12 into RGB using the standard rec.601 conversion matrix with a contrast stretch. That means very bright portions of the image are washed out, and very dark portions are crushed. The Brightness/contrast filter apparently works in YV12 if it's the first filter in the chain (at least in fairly recent versions of VirtualDub, ie 1.9.x). Turning the contrast down will allow you to retain those over-bright details. That gives later filters more bright detail to work with. Also try gradation curves in VirtualDub. http://members.chello.at/nagiller/vdub/index.html

[beetlespin]

i can honestly say the gradation curve gives me better results thus far. i can use this as a starting point then use other basic color adjustment filters for fine tuning, thanks.