20/05/2002: Added a few tips to the Lumband page.
03/04/2002: Uploaded a new, slightly optimised version of Pixellate and a new filter, Halftone.
VirtualDub is a powerful, albeit Windows only, piece of free software for pre and postprocessing video and working with avi files.
VirtualDub exposes a simple plugin API allowing third party plugins to be easily written. Even better, many have been written and are available in free form.
Bored after work one day I drowsily played around with the API and enjoyed the fact that writing VirtualDub filters gave instant results for very little effort.
These filters may also be used with the non-linear video editing package avisynth.
Whilst I suggest you check the pages below, for the impatient here is an archive of binaries of all the filters.
To install the filters, place the .vdf files in your virtualdub/plugins directory.
This filter creates a psychedelic effect by shifting the hues of pixels depending upon their luminescence value.
A simple pixellate filter, a stepping stone to my forthcoming halftone filter but potentially useful in its own right.
This filter cycles the hues of an image as the frame number increases. It can employed with luminescence band for added psychedelia!
This filter renders the input frame in 2 (user selectable) colours. It uses circles whose radii depend upon the luminescence of the input block to reproduce a version of the original image.
Thanks to Donald Graft for GPLing his filters from which the RGB<->HLS and GUI functions were taken (me lacking any kind of Win32 API documentation). Further thanks to Ian Roberts for beta testing and many useful suggestions. Finally to Avery Lee for the coolness in binary form that is VirtualDub.