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  interrupted  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)