Tone curve parameters. Each curve is a list of points joined by a smooth
curve that never overshoots between them (monotone cubic interpolation).
Points are sorted by input; a curve that does not start at input 0 or end
at input 1 gets the point (0, 0) or (1, 1) added.
Tone curve parameters. Each curve is a list of points joined by a smooth curve that never overshoots between them (monotone cubic interpolation). Points are sorted by input; a curve that does not start at input 0 or end at input 1 gets the point (0, 0) or (1, 1) added.