Raffriff42: link fix

2015-11-08T04:46:40Z

link fix

← Older revision		Revision as of 06:46, 8 November 2015
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	{{FilterCat4\|External_filters\|Plugins\|Restoration_filters\|~~Spatio~~-~~temporal_denoisers~~}}		{{FilterCat4\|External_filters\|Plugins\|Restoration_filters\|Spatial-Temporal_Denoisers}}
	{{Filter3		{{Filter3
	\|{{Author/Tom Barry}}, {{Author/Fizick}}		\|{{Author/Tom Barry}}, {{Author/Fizick}}

Reel.Deal: STMedianFilter

2015-03-31T04:03:07Z

STMedianFilter

New page

{{FilterCat4|External_filters|Plugins|Restoration_filters|Spatio-temporal_denoisers}}
{{Filter3
|{{Author/Tom Barry}}, {{Author/Fizick}}
|v.0.1.0.3
|[http://web.archive.org/web/20130207143129/http://neuron2.net/trbarry/STMedianFilter.zip STMedianFilter.zip]
|Spatio-temporal denoisers
|[http://www.gnu.org/licenses/gpl-2.0.txt GPLv2]
|6=
[http://forum.doom9.org/showthread.php?t=56107 Doom9 Thread]
[http://forum.doom9.org/showthread.php?t=89211 Doom9 Thread 2]}}
== Description ==
STMedianFilter is a (slightly motion compensated) spatial/temporal median filter. It fairly very fine grained, using only adjacent pixels in space and time, so it looks at the adjacent 26 locations to filter each location.
 
 
== Requirements ==
* AviSynth 2.5.8 or later
* Supported color formats: [[YUY2]], [[YV12]]

* [[SSE]] / [[MMX]] compatible CPU
 
== [[Script variables|Syntax and Parameters]] ==
:{{Template:FuncDef|STMedianFilter (clip, int, int, int, int)}}
 
::{{Par2| |clip| }}
:::Input clip; only luma will be processed.

::{{Par2| |int| }}
:::<tt>'''S_FilterThreshHold'''</tt>: don't spatial filter pixel if it would change it more than this. Larger values may cause loss of fine line detail but it's not extremely sensitive.

::{{Par2| |int| }}
:::<tt>'''S_EdgeThreshHold'''</tt>: don't spatial filter pixel if on an edge where vals change more than this. It seems fairly forgiving, so it can be raised a lot if desired.

::{{Par2| |int| }}
:::<tt>'''T_FilterThreshHold'''</tt>: don't temporal filter pixel if it would change it more than this. Large values will cause ghosting. Don't set over 5-10 to avoid ghosting.

::{{Par2| |int| }}
:::<tt>'''T_MotionThreshHold'''</tt>: don't temporal filter pixel if uncompensated motion vals change more than this. Don't set over about 10 to avoid ghosting.
 
::*S and T above stand for spatial and temporal, respectively.
::*Valid values for each are from 0 to 255. Larger values cause more filtering but more artifacts.
::*'''Note:''' all parameters are unnamed and do not have a default so they must be specified.
 
== Examples ==
A good starting point:
[[AviSource]]("Blah.avi")
STMedianFilter(8,15,4,7) # (S_FilterThreshHold, S_EdgeThreshHold, T_FilterThreshHold, T_MotionThreshHold)

 
==Method of Operation==
But if I understand it right a simple median filter is just a clipping step where a value is set to not extend past the high and low of its neighbors.

For instance, if you had 3 pixels in a row that had the values <5,8,7> you could clip the center one to not be outside the low of 5 or the high of 7,so you would set it to 7.

Now imagine you had a small 3x3 video screen, like one surface of a Rubik's cube. Imagine the previous frame was the bottom layer of the cube, the current frame was the middle layer, and the next frame was the top.

Then the current center pixel would be right in the center of the Rubik's cube and there would be 13 ways you could draw a line through it and a pair of two nearest neighbors.

What I did was to compare each of those pairs of neighbors to see which pair was most agreeing on value. I used that pair to clip the value of the center pixel.

I also clipped the pixel value only if both:

#It would not change the pixel value by more then the FilterThreshold parm value, and
# The amount of 'uncompensated motion' (agreement on value by neighbors) was less than the MotionThreshHold parm value.
 
== Changelog ==
Version Date Changes 
v0.1.0.3 2004/08/19 - [http://avisynth.nl/users/fizick/stmedian/stmedian.html Released by Fizick 2005/01/30]
- Fixed bug with spatial filter radius for YV12
v0.1.0.2 2004/08/10 - by Fizick - not public
- Fix one main bug (for both YUY2 and YV12 modes):
in all previous versions light pixels were not filtered,
both S_EdgeThreshHold and T_MotionThreshHold did not work also.
v0.1.0.1 2003/06/22 - Fix bug affecting YV12 only
v0.1.0.0 2003/01/22 - Remove chroma filtering again. Add YV12 support. Use Pluginit2
- Also remove Horizontal parms, add them to spatial.
- Hopefully fix purple tint.
v0.0.3.0 2002/08/03 - Add some chroma filtering
v0.0.2.0 2002/08/03 - Bugs, Split out spatial, Temporal, Horizontal user parms
v0.0.1.0 2002/08/02 - Initial test release
 

== Archived Downloads ==
{| class="wikitable" border="1"; width="600px"
|-
!!width="100px"| Version
!!width="150px"| Download
!!width="150px"| Mirror
!!width="150px"| Mirror 2
|-
!v0.0.1.3
|[http://web.archive.org/web/20130207143129/http://neuron2.net/trbarry/STMedianFilter.zip STMedianFilter.zip]
|[http://avisynth.nl/users/fizick/stmedian/stmedianfilter0103.zip stmedianfilter0103.zip]
|[http://avisynth.org.ru/stmedian/stmedianfilter0103.zip stmedianfilter0103.zip]
|}
 
== External Links ==
*[http://web.archive.org/web/20110627220738/http://neuron2.net/trbarry/Readme_STMedianFilter.txt Archive.org] - Original archived documentation. 
*[http://avisynth.org.ru/docs/english/externalfilters/stmedianfilter.htm avisynth.org.ru] - STMedianFilter documentation, [http://avisynth.org.ru/docs/russian/externalfilters/stmedianfilter.htm Russian].
*[http://forum.doom9.org/showthread.php?t=55266 Doom9 Forum] - Simple Temporal Median Filter.
 
 
-----------------------------------------------
'''Back to [[External_filters#Spatio-Temporal_Denoisers| External Filters]] ←'''

STMedianFilter - Revision history

Raffriff42: link fix

Reel.Deal: STMedianFilter