

	=============================
		Auto Levels
	    VirtualDub - Filter
	     (C) EOD & LC 2002
	=============================


The AutoLevels filter works stretching the levels separately for Red Green and Blue.

The amount of stretch is calculated using the values "Bright" and "Dark"
"Bright" defines the number of pixels that will be lost in the brightness.
"Dark" defines the number of pixels that will be lost in the darkness.

The maximum stretching is limited with "MaxGain" to prevent a eccessive noise
 amplification when the image is very dark.
 
The "White" and "Black" parameters defines the target (output) stretching levels.

The output color-temperature can be corrected using "Red", "Green" and "Blue" values.

This filter is very fast because all the precedent corrections are precalculated
The correction loop uses only lookup tables (in assembly)



KNOWN BUGS

- 29_10_2002 Horizzontal cropping do not works (it blacks the top part of the image).