This effect/filter changes Slope, Offset, and Power of the color components, and the overall Saturation, according to the ASC CDL (Color Decision List)
The effect has keyframes.
Changing the slope means multiplying the pixel value with a constant value. Black pixels will remain black, while brighter ones will be changed. All effects can be observed well when applied on a greyscale gradient and looking at the RGB Parade.
You can use this effect to achieve proper white balance.
Slope R / G / B / @ - Slope is the multiplier to the incoming data in the respective color channels. Allowed values are from 0 to 1000, default is 50.
Offset R / G / B / @ - Offset is a summation to the incoming data in the respective color channels. Allowed values are from 0 to 2048, default is 1024.
Power R / G / B / @ - Power is a power function (i.e. 22) to the incoming data in the respective color channels. Allowed values are from 0 to 1000, default is 50.
Overall Saturation - Changes the overall saturation. Allowed values are from 0 to 1000, default is 100.
This filter implements a standard way of color correction proposed by the American Society of Cinematographers: The Color Decision List, also known as the ASC CDL with the goal to exchange rudimentary color correction information between post-production tools.
The ASC CDL is a standard format for basic primary color correction (primary meaning affecting the whole image and not only selected parts).
Basically there are two stages in the correction:
SOP correction for each channel separately
Overall saturation correction
All corrections work on [0,1], so the RGB(A) values need to be transposed from [0,…,255] to [0,1].
out = in * slope; 0 <= slope < ∞
out = in + offset; -∞ < offset < ∞
out = in^power; 0 < power < ∞
Y = 0.2126 R + 0.7152 G + 0.0722 B(according to Rec. 709)
For all channels:
out = luma + sat * (in-luma)
As the values may exceed 1 (or 0), they need to be clipped where necessary.
See the Tips & Tricks chapter Waveform and RGB Parade where this effect is used to adjust the white balance of a clip.