Hue/Saturation/Intensity Filter for Virtual Dub
(Version 1.0 beta 6)

[Place this text file in the VirtualDub plugins directory to make
it available via the Help button on the filter configuration dialog
box. The computer must have a program called Notepad available in
its search path.]

This filter provides the ability to adjust the hue. saturation, and 
intensity of a video clip. It is valuable for fixing video clips that have
been captured with incorrect hue and/or saturation. The filter supports
active preview to simplify setting the desired adjustments. 

The following options are provided:

Hue: This option determines how much the hue is to be shifted. For example,
a shift of +120 shifts red to green, green to blue, and blue to red. The entire
hue range may be accessed by using negative shift values as required. For
example, to shift red to blue, use a shift value of -120.

Preserve luma on hue change: This option causes the filter to attempt to preserve
the luminance of input colors. This option interacts strangely with high saturation
values. This is currently under investigation and may improve in later versions. 

Saturation: This option determines how the saturation is to be adjusted.
The value may range from 0.0 to 5.0. A value of 0.0 produces a gray-scale
image. A value of 1.0 produces no saturation change. A value of 5.0 produces
a maximal increase of saturation.

Intensity: This option determines how the intensity is to be adjusted.
The value may range from 0.0 to 2.5. A value of 0.0 produces a black
image. A value of 1.0 produces no intensity change. A value of 2.5 produces
a maximal increase of intensity.

Apply To: This option determines the colors to which the adjustments are to
be applied. Check the boxes for the color ranges that you want to be affected.
Please be aware that combining selective application with large changes may
produce banding in the output image.

For additional information, version updates, and other filters, please
go to the following web site:

Filters for VirtualDub
http://www.geocities.com/Colosseum/Pressbox/8699/index.html

Donald Graft
March 24, 2000
(C) Copyright 2000, All Rights Reserved