Version 3.2.01 (Jan. 03, 2003)
This filter performs smoothing of the video material in time.
That means it does no smoothing across neighboring pixels.
I think this is quite reasonable, because the main source of the video noise is the electrical/thermal oscillations in time.
The reason why there are still so many filters that smooth the video in 2D is because smoothing in time can result in a well-known effect of the motion blur. SpotRemover attempts to overcome this problem.
I should acknowledge that the idea of the smoothing routine is borrowed from the temporal smoother filter of Avery Lee. And I am grateful to him for the best program for processing video, the VirtualDub.
However, I have completely redesigned the algorithm and made it more flexible.
Besides the time smoothing, SpotRemover has several other functions.
After the smoothing, the intensity and/or color can be dynamically locked in order to help the subsequent MPEG compression. This is similar to what the PicFix filter does (made by Gabest). But in SpotRemover, this is implemented more precisely and results in no artifacts during a slow intensity change (like panning over the sky).
Next, SpotRemover can enhance colors (brightness, contrast, saturation, and color shifts) on the fly with no effect on the final processing speed.
And finally (and this is the main purpose of the filter), this filter removes spots and scratches, which are always present in the movies made from old films. As long as the movies are shot on the films, you always have these annoying little blots.