Merge two images, here is the problem!

[color]

I was thinking of coloring a movie frame by frame with automatic colorization. Because it takes so mutch time with high resolution I was thinking on shrinking it. But here is the problem. I then want to add the colored pictures over the original video (grayscale) but only the colors so the picture has it sharpness. How do I do this and is this possible in avisynth?

It can be done in photo editors but it would take month to do it.

So can you "overlay" or what its called two video over each others?

[raffriff42]

B=(full size B/W clip)
C=(smaller color clip)
Overlay (http://avisynth.nl/index.php/Overlay)(B, C.BicubicResize(B.Width, B.Height), mode="chroma")

http://avisynth.nl/images/Layer-base-Lena.png http://avisynth.nl/images/Layer-over-grad.png http://avisynth.nl/images/Overlay-example-chroma.png

EDIT another way -B=(full size B/W clip)
C=(smaller color clip)
MergeChroma (http://avisynth.nl/index.php/MergeChroma#MergeChroma)(B, C.BicubicResize(B.Width, B.Height))

[color]

Thank you, that solves my problem! :D