RadiaLum filter for VirtualDub - Version 2.1

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


General description

It 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 center 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 colors too.

Parameters

Center:

Defines the amount of radial luminance correction applied in the center of the frame. Leftmost (0) means no correction at all. Rightmost (100) means maximum correction.


Border:

Defines the amount of radial luminance correction applied in the borders of the frame. Leftmost no correction, rightmost maximum correction.


Global:

This is a sort of luminance control. It interacts with the above two controls.


Interlaced:

Check it if the source clip frames are interlaced.


Keep chroma:

This flag affects the way pixels are changed when increasing brightness. If you check it, the color of pixels is kept while correcting border to white.


Invert:

If you check it, the correction is inverted that is: center gets brighter and border gets darker.


Title disable threshold:

This is a trick I use to disable the filter on solid titles. If it is set less than 255 the filter looks at 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 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:

It shifts the clip colors between green and red.


Yellow-Blue:

It shifts the clip colors between yellow and blue.


Buttons

Disable Filtering

While in preview mode, this button allows to enable/disable the filter to check for differences.


Sample frame

Forces to sample the current preview frame in the shown histogram.



© Alessandro Malanca - Dec / 2002