yuvmedianfilter - A filter for yuv images produced by the mjpeg tools
] [-R num
] [-T num
] [-I num
] [-s num
] [-v num
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.
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)
- 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)
- Print out a help message
It is slow. Using a radius greater than the default of 2 is painfully slow.
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:
- For more info, see our website at