Virtual Dub - Colors Adjust filter

[Place this text file in the VirtualDub plugins directory]
© Alessandro Malanca - Jul / 2002

This filter allows you to adjust colors in RGB space using an approach similar to the one used in YUV space. Pratically for each RGB= (R,G,B) pixel, Luma is assumed (more or less) as Luma= MIN(R,MIN(G,B)) and chromatic components as : Red= (R-Luma), Green=(G-Luma), Blue= (B-Luma). Here on the usal corrections gain, offset and gamma are applyed to the 4 channels (Luma,R,G,B). Moreover the additional 3 dimensional channel GLOBAL (Red,Green,Blue) allows you to adjust the global color saturation.

Controls description

Select Chan.

This button selects the current channel: luma - global - Red - Green - Blue. Corrections are applied to the selected channel.

Offset sliders

Corrects the brightness globally and for red, green or blue colour.

Gamma sliders

Corrects the gamma (mid tones luminance) globally and for red, green or blue color.

Gain sliders

Corrects the contrast globally and for red, green or blue colour.
Balance media: This value is the reference point for brightness control. Values above are incremented, and below are decremented. You can also set it to 0 to have the usual contrast control.

Colors histogram

In preview mode, shows the distribution of pixel values from 0 to 255; globally and for red, green or blue.
Max: is the amount of points indicated by the histogram max value.

© Alessandro Malanca - Jul / 2002