NAME

       pammixinterlace - mix adjacent lines to merge interlaced images

SYNOPSIS

       pammixinterlace

       [-filter={linear, fir, ffmpeg}]

       [-adaptive]

       [infile]

DESCRIPTION

       This program is part of Netpbm(1).

       pammixinterlace is meant to operate on an image which is the interlacing of two images, where raster rows
       0,  2,  4, etc. are from one image and rows 1, 3, 5, etc. are from another.  (See below for why you might
       expect to encounter such an image).

       pammixinterlace makes each row of the output a mixture of the corresponding row of the input and its  two
       neighbors.  It uses half of the main row and a quarter each of the two neighbor rows.

       This  can  be useful if the image is a video capture from an interlaced video source.  In that case, each
       row shows the subject 1/60 second before or after the two rows that  surround  it.   If  the  subject  is
       moving, this can detract from the quality of the image.

       In video data streams, you often find each frame contains only half the rows of the image -- the odd half
       or  the  even  half.  The displayer of the stream displays the rows in their proper positions on a CRT as
       they come in.  When you display the rows in this order, the CRT has less  flicker  because  a  particular
       area  of  the screen gets refreshed twice as often.  In the process of capturing such a stream, computers
       often generate the interlaced image of the type that pammixinterlace works  with.   But  this  interlaced
       image,  when  displayed  on  a  CRT,  does  not look the same as if a displayer were rendering the stream
       directly on a CRT as it arrived, because of  the  timing  of  when  the  various  pixels  get  drawn  and
       subsequently fade.  That's why you need something like pammixinterlace.

       You may prefer the effect of simply extracting one of two images.  You can do that with pamdeinterlace.

OPTIONS

       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet, see  Common
       Options ), pammixinterlace recognizes the following command line options:

       -filter={linear,fir,ffmpeg}
              This option chooses between one of the three  filtering  mechanisms.   linear  is  a  linear-blend
              formula.   fir  is  a  size-5  FIR  low-pass  filter,  and  ffmpeg  is  a  formula pulled from the
              documentation of the program ffmpeg .

              The default is fir.

       -adaptive
              This option turns on "adaptive" filtering mode.  In this mode pammixinterlace modifies only pixels
              that are obviously part of a "comb" pattern.

SEE ALSO

       pamdeinterlace(1), pam(1) pnm(1)

DOCUMENT SOURCE

       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The  master  documentation
       is at

              http://netpbm.sourceforge.net/doc/pammixinterlace.html

netpbm documentation                            22 February 2007                  Pammixinterlace User Manual(1)