Manual: pammixinterlace

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 dis‐
       player 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)