This filter is not yet optimized for speed. Optimizations will be included in a future version.
The justification for the filter is simple. The biggest complaint about Unsharp Mask (for example) is that setting the strength high enough to sharpen important edges also amplifyies noise and small detail. MSharpen solves this problem effectively by detecting important edge areas and then applying sharpening only to those areas. You first set the 'threshold' parameter so that desired edges are selected. Then you set the sharpening strength. You can set very high sharpening strengths without amplifying noise or fine detail (because the edge map is used to mask the sharpening).
There is an important caveat about the use of this filter. It works best on frames obtained from progressive source material, such as films and anime. Although it can be used on deinterlaced video, if the deinterlacing is poor or applied weakly, this filter can emphasize the residual combing, because it sharpens the important edges; these edges are where the most combing occurs! So be aware of this. All filters have their domains of application, and it would be a mistake to think of any filter as a panacea.
Strength: This is the strength of the sharpening to be applied to the edge detail areas. It is applied only to the edge detail areas as determined by the 'Threshold' option. Strength 255 is the strongest sharpening.
Threshold: This parameter determines what is detected as edge detail and thus sharpened. To see what edge detail areas will be sharpened, use the 'Show sharpened areas' option.
Show sharpened areas: When checked, the areas to be sharpened are shown in white against a black background. Use this to set the level of detail to be sharpened. This function also makes a basic edge detection filter.
Copyright (C) 2002, Donald A. Graft, All Rights Reserved.
Feedback/inquiries to neuron2@attbi.com.
For updates and other filters/tools, visit my web site:
http://shelob.mordor.net/dgraft/