You can find this filter through
->->.
Images captured by videocards, especially when fast movement
is recorded, may look blurred and stripped, with splitted
objects. This is due to how cameras work. They don't record
25 images per second, but 50, with half vertical resolution.
There are two interlaced images in one frame. First line of
first image is followed by first line of second image
followed by second line of first image... etc. So, if there
have been an important move between the two images, objects
will appear splitted, shifted, stripped.
The Deinterlace filter keeps only one of both images and
replaces missing lines by a gradient between previous and
following lines. The resulting image, or selection, will be
somewhat blurred, but can be improved by enhance filters
A test image can be found at www.alparysoft.com
