ppmtoyuv

   Updated: 06 March 2003
   Table Of Contents

NAME

   ppmtoyuv - convert a PPM image to an Abekas YUV file

SYNOPSIS

   ppmtoyuv [ppmfile]

DESCRIPTION

   This program is part of Netpbm.

   ppmtoyuvReads  a PPM image as input and produces an Abekas YUV
file as
   output.

   The output file contains a raster of four byte YUV codes, each
uniquely
   associated  with  two  side-by-side	pixels	in the image. The
raster contains
   rows in order from top to bottom, and within each row  columns
from left to
   right. So the output file size in bytes is twice the number of
pixels in the
   image.

   Each YUV code is associated with two pixels from the input im-
age that we
   will	 call the left pixel and the right pixel. The 2nd byte of
the code is
   the Y value of the left pixel. The 4th byte of the code is the
Y value of
   the right pixel. The 1st byte of the code is an average of the
U value of
   the pixel to the left of the left pixel, the left  pixel,  and
the right
   pixel.  The	3rd  byte  of the code is analogous for V values.
These averages
   are weighted arithmetic means where the left pixel is weighted
double what
   the other two pixels are weighted.

SEE ALSO

   yuvtoppm, ppmtoeyuv, ppmtoyuvsplit, ppm

AUTHOR

   Marc	  Boucher marc@PostImage.COM, based on Example Conversion
Program,
   A60/A64 Digital Video Interface Manual, page 69.

   Copyright (C) 1991 by DHD PostImage Inc.

   Copyright (C) 1987 by Abekas Video Systems Inc.
     _________________________________________________________________



Table Of Contents

     * NAME
     * SYNOPSIS
     * DESCRIPTION
     * SEE ALSO
     * AUTHOR

UNIX/Linux commands referenced on this page:

1. convert
2. as
3. file
4. top
5. size
6. yuvtoppm
7. ppmtoeyuv
8. ppmtoyuvsplit