Video too redish

[bairradino]

My Panasonic DV camera acentuates the red color (it's not colorcast! When shooting red subjects this color is too bright).
How can I correct this?

[Nightshiver]

Turn the contrast down on your camera? Or lower the color levels?

[bairradino]

The video is already shooted......

[thetoof]

You can apply color correction with coloryuv() by using negative values of gain_v or off_v
or
Play with Tweak() (http://avisynth.org/mediawiki/Tweak) to lower the saturation of the reddish areas of the image.

[Comatose]

I'd go with Tweak and using hue to select the red areas then reduce saturation only for them, since it does sound like oversaturation :E

[Nightshiver]

I would have suggested tweak but I didn't think that his problem was on an already captured video. My mistake. But I agree, Tweak would work very well in this case.

[sidewinder711]

1. FixChromaBleeding

Some time ago I found a script from A. Jordan. He has a website (http://www.geocities.com/alex_j_jordan/index.htm) as well giving you a good example how it works. For me it worked perfectly on oversaturated blue and red parts of the footage.

LoadPlugin("ChromaShift.dll")
AVISource("movie.avi")
ConvertToYV12
FixChromaBleeding

Function FixChromaBleeding (clip input) {

# prepare to work on the V channel and reduce to speed up and filter noise
area = input.tweak(sat=4.0).VtoY.ReduceBy2

# select and normalize both extremes of the scale
red = area.Levels(255,1.0,255,255,0)
blue = area.Levels(0,1.0,0,0,255)

# merge both masks
mask = MergeLuma(red, blue, 0.5).Levels(250,1.0,250,255,0)

# expand to cover beyond the bleeding areas and shift to compensate the resizing
mask = mask.ConvertToRGB32.GeneralConvolution(0,"0 0 0 0 0 1 1 1 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0").ConvertToYV12

# back to full size and binarize (also a trick to expand)
mask = mask.BilinearResize(Width(input),Height(input)).Levels(10,1.0,10,0,255)

# prepare a version of the image that has its chroma shifted and less saturated
input_c = input.ChromaShift(C=-4).tweak(sat=0.8)

# combine both images using the mask
return input.overlay(input_c,mask=mask,mode="blend",opacity=1)
}


Regarding optimizing the mask part (using masktools instead of GeneralConvolusion), here in the forum the following was suggested:

# expand to cover beyond the bleeding areas and shift to compensate the resizing
#mask = mask.ConvertToRGB32.GeneralConvolution(0,"0 0 0 0 0 1 1 1 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0").ConvertToYV12
#with (using MaskTools v1.5.x)

mask = mask.DEdgeMask(0,255,0,255,"0 0 0 1 0 0 0 0 0").DEdgeMask(0,255,0,255,"1 1 1 1 1 1 0 0 0")


2. TweakColor

Another possibility is using TweakColor (http://forum.doom9.org/showthread.php?s=&threadid=74334) created by Trevlac. You can try to reduce the saturation of red highs with:
TweakColor(sat=0.75,startHue=80,endHue=140,maxSat=115,minSat=75)

Greetz

[bairradino]

Thank you guys.
You are great!

[Gavino]

Another possibility is using TweakColor (http://forum.doom9.org/showthread.php?s=&threadid=74334) created by Trevlac. You can try to reduce the saturation of red highs with:
TweakColor(sat=0.75,startHue=80,endHue=140,maxSat=115,minSat=75)
If using Avisynth 2.58, this functionality is now included in the standard Tweak.

[bairradino]

@gavino

Yes.
But it seems that VirtualBub doesn't "like" Avisynth 2.58

[Wilbert]

Yes.
But it seems that VirtualBub doesn't "like" Avisynth 2.58
What do you mean?

[bairradino]

I installed "AviSynth_080622.exe", and when I load an Avisynth script in VirtualDub v1.8.5 it's window disappear.
I had to reinstall Avisynth 2.57
It happened only me?

[Wilbert]

I installed "AviSynth_080622.exe", and when I load an Avisynth script in VirtualDub v1.8.5 it's window disappear.
Post your script and empty your plugin folder before trying it again.

[bairradino]

@wilbert

You're right.
After your suggestion I remebered one time that happened the same because of a wrong function.
So, I cleaned the plugins folder, than copy functions and plugins, 4 each time, and proved VirtualDub with Avisynth 2.58.
I discovered the problem; I had (don't know how) the library avisynth.dll (version 2.57). That's why it worked with version 2.57 and was in conflit with version 2.58
Thanks for your help... and your knowledge.

[srigopaldaliya]

I read the above suggestion for reducing the red color....

In one of my case, the Video is very blueish... What should i do to bring back it to normal colors?

[thetoof]

Same thing with Tweak(), but with a different hue range.
With ColorYUV(), use negative values for gain_u or off_u.

[2Bdecided]

If using Avisynth 2.58, this functionality is now included in the standard Tweak.I'd missed that - that's really cool.

Cheers,
David.