logo Sign In

Post #785848

Author
archimedes
Parent topic
Color matching and prediction: color correction tool v1.3 released!
Link to post in topic
https://originaltrilogy.com/post/id/785848/action/topic#785848
Date created
21-Aug-2015, 2:21 PM

Ive tried two ways to implement the mapping from one frame to another in multiple rotations. 

The first is the one you described. The problem here is that there are still many-to-many mappings in the rotated color spaces. Granted, the ranges are usually pretty narrow, but this has still an effect along all rotations. My algorithm selects the value which is most often mapped. So, there is information lost in each rotation. This is why only few rotations in different frames will get the correct colors for those rotations, but not for many rotations. 

The second one only works for frames of the same shot. I've noticed that each RGB color of the input frame is mapped to exactly one RGB color in the full rotated colored output frame. In my tests, there were usually about 50k-60k unique colors in one frame. So it's hardly enough to recolor a whole film based on a single frame, using this method. However, if I use the color transfers of the reference frame, I can usually correctly recolor 95% to 99% of the pixel of the same shot frames. The remaining pixels are recolored according to the mapping function obtained from simple histogram matching.