https://bugs.kde.org/show_bug.cgi?id=355747
--- Comment #6 from rebuilders...@gmail.com --- Thank you, Wolthera, for taking the time to work on this! I'm looking at this filter now in 4.0 alpha, and it does seem to work on float images fine. I started thinking that since this is done, being able to clone the Grade node's functionality should be fairly close now. I've puzzled out the transforms for turning Blackpoint, Whitepoint, Gamma, into Slope,Offset, Power and got the following expression in Nuke for calculating RGB: S= 1 / (whitepoint - blackpoint) O= -1 * blackpoint *s P = 1 / gamma and getting RGB: R=pow( R * S + O ,P) G=pow( G * S + O ,P) B=pow( B * S + O ,P) So e.g. red = (R*S+O)^P The results from this match with the results from the Grade node in Nuke, so the math seems correct. However, when I set e.g blackpoint to 0.1, I get these values for SOP: S= 1.1111... O=-0.1111... P=0.65 So I'd expect that in Krita, to do this transform, I'd need to set S O P to approx. 72815, -7280, 42598. This can't be done, since the values available in the filter are clamped to 0..65535. Is this a hard limitation currently? Is there a way to use this tool to e.g. multiply the image by values over 1? It seems not at the moment, as that would require values over 65535 for the controls. Thanks again for the work, and sorry for pestering you here! I hope I'm not too unclear on what I'm going on about. -- You are receiving this mail because: You are watching all bug changes.
