Here is an avisynth script that I worked up that TRIES to match the colors of one source with another. Your mileage may vary. Feel free to comment, leave feedback, suggestions, examples etc. here.

Function RGBMatch(clip gref, clip bref, clip “input”, int “mix”)

{# v1.2 - by G-force

Make Red, Green and Blue channel average, (and min and max) of second clip match first clip

or optionally, make third clip match difference between first two

i.e., if the cropping is different between the sources, you could crop the sources first<

to better match each other and then only apply the result to the third (uncropped) clip

mix = how much min/max compensation to do, 0=none (average only), 255=fully match min/max (default)

input = Default(input,bref)

mix = Default(mix,255) 

global gref = gref

global bref = bref

global input = input

global mix = mix

scriptclip(bref,"""

grefrgb=gref.ConvertToRGB()

brefrgb=bref.ConvertToRGB()

inputrgb=input.ConvertToRGB()




grefr = grefrgb.ShowRed().ConvertToYV12()

grefg = grefrgb.ShowGreen().ConvertToYV12()

grefb = grefrgb.ShowBlue().ConvertToYV12()

brefr = brefrgb.ShowRed().ConvertToYV12()

brefg = brefrgb.ShowGreen().ConvertToYV12()

brefb = brefrgb.ShowBlue().ConvertToYV12()

inr = inputrgb.ShowRed().ConvertToYV12()

ing = inputrgb.ShowGreen().ConvertToYV12()

inb = inputrgb.ShowBlue().ConvertToYV12()




y1r = AverageLuma(grefr)

y1g = AverageLuma(grefg)

y1b = AverageLuma(grefb)




y2r = ((255-mix)0+mixYplanemin(grefr))/255

y2g = ((255-mix)0+mixYplanemin(grefg))/255

y2b = ((255-mix)0+mixYplanemin(grefb))/255




y3r = ((255-mix)255+mixYplanemax(grefr))/255

y3g = ((255-mix)255+mixYplanemax(grefg))/255

y3b = ((255-mix)255+mixYplanemax(grefb))/255




x1r = AverageLuma(brefr)

x1g = AverageLuma(brefg)

x1b = AverageLuma(brefb)




x2r = ((255-mix)0+mixYplanemin(brefr))/255

x2g = ((255-mix)0+mixYplanemin(brefg))/255

x2b = ((255-mix)0+mixYplanemin(brefb))/255




x3r = ((255-mix)255+mixYplanemax(brefr))/255

x3g = ((255-mix)255+mixYplanemax(brefg))/255

x3b = ((255-mix)255+mixYplanemax(brefb))/255




#compute coefficients for y=ax^2+bx+c using min, avg, max




ar = x1r==x2r? 0: x1r==x3r? 0: x2r==x3r? 0:

 \ (y3r-y1r+(x1r-x3r)(y1r-y2r)/(x1r-x2r))/((x1r-x3r)(x2r-x3r))

br = x1r==x2r? 0:

 \ ((y2r-y1r)/(x2r-x1r))-ar*(x1r+x2r)

cr = y1r-arx1rx1r-br*x1r




ag = x1g==x2g? 0: x1g==x3g? 0: x2g==x3g? 0:

 \ (y3g-y1g+(x1g-x3g)(y1g-y2g)/(x1g-x2g))/((x1g-x3g)(x2g-x3g))

bg = x1g==x2g? 0:

 \ ((y2g-y1g)/(x2g-x1g))-ag*(x1g+x2g)

cg = y1g-agx1gx1g-bg*x1g




ab = x1b==x2b? 0: x1b==x3b? 0: x2b==x3b? 0:

 \ (y3b-y1b+(x1b-x3b)(y1b-y2b)/(x1b-x2b))/((x1b-x3b)(x2b-x3b))

bb = x1b==x2b? 0:

 \ ((y2b-y1b)/(x2b-x1b))-ab*(x1b+x2b)

cb = y1b-abx1bx1b-bb*x1b




inr=inr.MT_lut(“x x * “+string(ar)+” * x “+string(br)+” * + “+string(cr)+” +”).ConvertToRGB()

ing=ing.MT_lut(“x x * “+string(ag)+” * x “+string(bg)+” * + “+string(cg)+” +”).ConvertToRGB()

inb=inb.MT_lut(“x x * “+string(ab)+” * x “+string(bb)+” * + “+string(cb)+” +”).ConvertToRGB()




MergeRGB(inr,ing,inb)




ConvertToYV12()




""")




Return(last)}