1Pamvalidate User Manual(0)                          Pamvalidate User Manual(0)
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NAME

6       pamvalidate - validate Netpbm image format
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SYNOPSIS

10       pamvalidate
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DESCRIPTION

15       This program is part of Netpbm(1).
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17       pamvalidate  copies a Netpbm image from Standard Input to Standard Out‐
18       put, except that if there are certain violations of the image format in
19       the input, pamvalidate fails without producing any output.
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21       This  is  most  useful  in a pipeline, before a stage you don't want to
22       start working on Netpbm input until it knows it can  get  all  the  way
23       through  it.   For example, assume you are converting PPM images to PNG
24       and you don't want to produce a partial  PNG  file  under  any  circum‐
25       stance.  If you just use pnmtopng, and the PPM input is truncated half‐
26       way through the raster, pnmtopng fails, but also produces about half of
27       a  PNG  file.  To prevent that, pass your PPM input through pamvalidate
28       on its way to pnmtopng.  Then, pamvalidate will fail, and  consequently
29       the  pipeline  will fail, before pnmtopng has seen any input and there‐
30       fore before pnmtopng has produced any output.
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32       These are the kinds of format violations pamvalidate detects:
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36       ·      A purported sample value exceeds the declared maxval.
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38       ·      The stream ends prematurely.
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41       This program works on multi-image streams,  producing  a  corresponding
42       output stream.
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44       See pamfix for a way to salvage an invalid Netpbm image stream.
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OPTIONS

49       None.
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SEE ALSO

54       pam(1) pnm(1) pamfix(1)
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HISTORY

59       pamvalidate was new in Netpbm 10.66 (March 2014).
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DOCUMENT SOURCE

62       This  manual  page was generated by the Netpbm tool 'makeman' from HTML
63       source.  The master documentation is at
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65              http://netpbm.sourceforge.net/doc/pamvalidate.html
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67netpbm documentation             22 March 2014      Pamvalidate User Manual(0)