Some way to increase luma values over a specific limited range?

[cobo]

Is there a way to increase or decrease luma values over a specific limited range in a black and white film?

Using ColoyYUV and Tweak the best I can do is either an image where the dark greys look good but the light greys are too washed out, or the light greys are good and the dark greys are too dark.

[Pookie]

http://www.avisynth.org/stickboy/jdl-range.avsi


http://forum.doom9.org/showthread.php?p=868799#post868799

[cobo]

Thanks Pookie. Those look promising.

Also came across a suggestion to use lut-tool of Masktools for something somewhat similar in this thread, which might be useful for what I want to do if I can get a handle on the math needed to express it.
http://forum.doom9.org/showthread.php?t=115072

[foxyshadis]

You can load a GIMP or PSP-compatible saved curves file into GiCoCu, to apply curves processing. I think you can also specify a collection of x,y point pairs in lieu of a file. Luts can do the same thing, but the syntax is much harder to handle than a curves GUI, or even a specified collection of points that the curve is built from.

[cobo]

Thanks for the tip about GiCoCu foxyshadis. It took a couple dozen trys before I found just the right curve. Both Hdr_Agc and GiCoCu provided improvement, but a combination of the two acheived a better result than with either alone.

[espy2]

GiCoCu - is there a trick to making it work correctly? I tried it (several clips, all options, exhaustively) and just got bad results such as a yellowish image. Any pointers in the right direction would be welcome.