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GNU/Linux man pages

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ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

GNU/Linux

CentOS 5.1

pammixinterlace(1)



pammixinterlace

Updated: 02 July 2005
Table Of Contents

NAME

pammixinterlace - mix adjacent lines to merge interlaced images

SYNOPSIS

pammixinterlace [infile]

DESCRIPTION

This program is part of Netpbm.

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.

SEE ALSO

pamdeinterlace, pam pnm
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Table Of Contents

* NAME
* SYNOPSIS
* DESCRIPTION
* SEE ALSO



pammixinterlace(1)