man > pammixinterlace(1)

Pammixinterlace User Manual(1)         General Commands Manual        Pammixinterlace User Manual(1)

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  ar‐
       rived,  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 ]8;;index.html#commonoptions\ Common Options]8;;\ ), pammixinterlace recognizes the following command line options:




       -filter={linear,fir,ffmpeg}
              This option chooses between one of the three filtering mechanisms.  linear is  a  lin‐
              ear-blend  formula.   fir  is  a  size-5  FIR low-pass filter, and ffmpeg is a formula
              pulled from the documentation of the program ]8;;http://ffmpeg.mplayerhq.hu\ffmpeg]8;;\ .

              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)