Secondary color correction: adding yellow to green

[videoFred]

Hello everybody,

For my work with old 8mm films, I often have to correct the green colors. For now, I do this with Tweak(). With "starthue" and "endhue" I can select the green color and then I can change the hue on the green channel only.

Examples:
http://www.super-8.be/Doom/VideoFred_Autoadjust_AvspMod_001.jpg
http://www.super-8.be/Doom/VideoFred_Autoadjust_AvspMod_002.jpg
http://www.super-8.be/Doom/VideoFred_Autoadjust_AvspMod_003.jpg

This works pretty good, but it can be better, sometimes it looks artificial. What I need is to mix some yellow in the greens.

I think this can be done with masktools, but this is beyond my knowledge...

Can someone help me here? Thanks in advance!

Fred.

[feisty2]

masktools?
I guess mt_lut is not a good idea for color adjustments due to the low output precision
you may want dither_lut16

[wonkey_monkey]

Could this be a job for selectivecolour (http://forum.doom9.org/showthread.php?t=151259)? You could try something along the lines of:


# input must be RGB32
selectivecolour(clip,\
0,0,0,\
0,0,0,\
-0.5,-0.5,0,\
0,0,0,\
0,0,0,\
0,0,0,\
false)

(not tested)

[raffriff42]

Take a look at "Smooth hue adjustment using Masktools?"
My solution: http://forum.doom9.org/showthread.php?p=1670559#post1670559
Gavino's solution is immediately below [EDIT and HappyLee's is above] All are similar and work well, although they are slow. What you would do is isolate the color you want to change with the hue and range arguments and than adjust the hue on that one color only. But be advised,as brilliant as avisynth is, this looks like a job for resolve lite

http://www.blackmagicdesign.com/au/support/detail?sid=3948&pid=11735&os=win
[scroll down, look for "DaVinci Resolve Lite"]

it's free... and it's worth having as not so long ago this program was $75k+...

resolve will do all the colour/tone fixes you'll ever need, though noise reduction is still avisynth's domain.

[Wilbert]

Try HSVAdjust (http://forum.doom9.org/showthread.php?t=162022).

[videoFred]

Thank you all for the hints!
I'm going to test it all out...

Fred.

[Mounir]

Ain't nothing better than a good vdub filter working in rgb imo, see below (2. Now followes color balance):
http://www.engon.de/audio/vhs4_en.htm

The RGBEQ filter linked on the same page is great (you can use 5 or more sliders to fix colors in narrow spaces.. so to speak)

the filter cmyk is great too (simpler though)