yuvmedianfilter(1) MJPEG tools manual yuvmedianfilter(1)
NAME
yuvmedianfilter - A filter for yuv images produced by the mjpeg tools
SYNOPSIS
yuvmedianfilter [-r num] [-R num] [-t num] [-T num] [-I num] [-f] [-w num] [-s num] [-v num] [-h]
DESCRIPTION
yuvmedianfilter is designed to enhance/filter images. It takes the input from STDIN and writes output to STDOUT.
This filter looks around the current point for a radius and averages the values that fall inside a threshold. So the image is softened and
the edges become more sharp. If the input material is noisy (it is always noisy but you do not always see it) the output images are
improved and the encoder spends less bandwidth encoding noise. The more sophisticated version of image filtering is yuvdenoise. But you
can use both programs in the encoding procces. It cannot process a recorded file and write the improved version to another file.
OPTIONS
yuvmedianfilter accepts the following options:
-r num
Radius for luma median (default: 2 pixels)
-R num
Radius for chroma median (default: 2 pixels)
-t num
Trigger threshold for luma (default: 2 [0=disable])
-T num
Trigger threshold for chroma (default: 2 [0=disable])
-I num
Interlacing type (0=no, 1=yes, default: taken from yuv stream)
-f Fast mode, i.e. the threshold is ignored, and a simple mean of the surrounding values is calculated.
-w num
In fast mode, the weight given to the current value versus the surrounding values. Default is 8.
Note that certain combinations of radii and weights have been optimized to be even faster -- radius 1 and weight 2.667, radius 1 and
weight 8, and radius 2 and weight 8.
-c num
In slow mode, more than this fraction of the pixels must be within the threshold; otherwise the pixel is simply the weighted mean of
pixels within a radius of 1. Default is 0.33333.
-s num
Number of beginning frames to skip. The first num frames are written to stdout unfiltered. This is useful for resuming an inter-
rupted job without having to duplicate work.
-v num
Verbosity level (0, 1 or 2)
-h Print out a help message
BUGS
It is slow. Using a radius greater than the default of 2 is painfully slow.
AUTHOR
This man page was written by Bernhard Praschinger.
The yuvmedianfilter program was written by Mike Bernson, and adapted to the yuv4mpeg2 stream header format by Steven M. Schultz.
If you have questions, remarks, problems or you just want to contact the developers, the main mailing list for the MJPEG-tools is:
mjpeg-users@lists.sourceforge.net
For more info, see our website at
http://mjpeg.sourceforge.net
SEE ALSO
mjpegtools(1), jpeg2yuv(1), lav2yuv(1), mpeg2enc(1), ppmtoy4m(1), yuv2lav(1), yuvdenoise(1), yuvscaler(1)
MJPEG Linux Square 24 February 2003 yuvmedianfilter(1)