RadiaLum
Filter for Virtual Dub - Version 2.0
(c) Alessandro Malanca - Jun / 2002
http://web.tiscali.it/minomala/index.htm
[Place this text file in the
VirtualDub plugins directory]
Performs
a radial intra-frame luminance correction. It has been developed to correct
luminance for films shoot from 8 mm and Super 8 sources. Such a films normally
have the centre of the frame that is brighter than the border. The filter uses
a tstudent function to correct the luminance. It
allows adjusting luminance and rgb colours too. I suggest you to use it also if
you need just a brightness, contrast, colours correction filter. I think it
allows for better corrections than standard filters. It can go faster than a
standard correction filter because of the algorithm I use: it builds, according
to user selected parameters, 3 pixel remapping vectors, so no calculus at all
are performed while processing frames (except for radial correction). Controls
are not as much sensitive, but I think the best correction is no corrections at
all; if you need more correction just ask.
Parameters description:
Radial correction:
Defines the amount of
radial luminance correction applied.
Leftmost (0) means no correction at all. Rightmost means (100) maximum
correction.
Radius:
Allows to change the
radius of the correction, moving left you concentrate the dark correction to
the centre, moving right you spread the correction to the borders.
Interlaced:
Check it if the source
frames are interlaced.
Title disable threshold:
This is a trick I use to
disable the radial correction on solid titles. If it is less than 255 it looks
for the top-leftmost and top- rightmost five dots of each frame. If the average
luminance of these ten dots is above the given threshold, the radial filtering
is disabled. (I use to force some white dot, in the top corners of the titles).
Brightness:
Globally correct the
luminance.
Contrast:
Corrects the frame
contrast.
Green-Red:
Adjust colours from
green to red.
Yellow-Blue:
Adjust colours from yellow
to blue.
Disable Filtering:
While in preview mode,
this button allows to enable/disable the filter applied to check differences.
Sample frame:
Forces
to sample the current preview frame in the shown histogram.