From Avisynth wiki
Jump to: navigation, search
Author Tom Barry
Download UnFilter.zip
Category Adjustment filters
License GPLv2
Discussion Doom9 Thread



UnFilter is a simple and reasonably fast Avisynth Soften/Sharpen filter.

It implements 5-tap user adjustable horizontal and vertical filters designed to (slightly) reverse previous efforts at softening or edge enhancement that are common (but ugly) in DVD mastering. Since DVDs were intended originally for interlaced displays this has caused content providers to vertically filter them even a bit more to hide interlacing artifacts. They sometimes overdo the edge enhancement.

When softening it will attempt to approximate the inverse of a simple 3-tap edge enhancement filter. When sharpening it will attempt to approximate the inverse of a simple 3-tap softening filter. For the math and logic involved see the comments in the UnFilterALL.inc member included in zip file.

The effects are fairly mild but be aware that excessive sharpening makes things harder to compress and may bring about the dreaded "edge enhancement artifacts" the people complain about in DVDs from some studios. And while excessive softness may hide noise it loses detail and generally just looks ugly. So it is probably best to just try to reverse whatever has already been done to your source.

UnFilter should run on all MMX machines or higher. It has also has some added code for 3DNOW instructions for when it is running on a K6-II or higher and some SSEMMX for P3 & Athlon.


Syntax and Parameters

UnFilter (clip, int, int)

clip =
Input clip.

int =
int =
HSharp, VSharp: horizontal and vertical sharpness. Valid values are from -100 (max softness) through zero (neutral) through +100 (max sharpness).
Note: all parameters are unnamed and do not have a default so they must be specified.


Extreme sharpening:

UnFilter(100, 100) # (HSharp, VSharp)


2003/01/18   V   - Use AvisynthPluginInit2
2002/11/25   V   - YV12 support - Don't mess with chroma
2002/11/13   V   - YV12 support
2002/06/29   V   - Fix more brain dead mistakes relating to low parm vals
2002/06/29   V   - Added version info
                         - Fixed bug on UnFilter(30,30)
                         - Fixed bug that might crash MMX machines
2002/06/28   V   - Initial test release V 0.1 (had no version info)

Archived Downloads

Version Download Mirror
v0.0.1.5 UnFilter.zip UnFilter.zip

External Links

Back to External Filters

Personal tools