Free Knowledge Resources


Linux Manual Pages


Free Software * Books

Source Code

Free Media

Linux

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
        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)



Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.



Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.



Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.



Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.


birds banner