Pamvalidate User Manual(1) General Commands Manual Pamvalidate User Manual(1)
NAME
pamvalidate - validate Netpbm image format
SYNOPSIS
pamvalidate
DESCRIPTION
This program is part of Netpbm(1).
pamvalidate copies a Netpbm image from Standard Input to Standard Out-
put, except that if there are certain violations of the image format in
the input, pamvalidate fails without producing any output.
This is most useful in a pipeline, before a stage you don't want to
start working on Netpbm input until it knows it can get all the way
through it. For example, assume you are converting PPM images to PNG
and you don't want to produce a partial PNG file under any circumstance.
If you just use pnmtopng, and the PPM input is truncated halfway through
the raster, pnmtopng fails, but also produces about half of a PNG file.
To prevent that, pass your PPM input through pamvalidate on its way to
pnmtopng. Then, pamvalidate will fail, and consequently the pipeline
will fail, before pnmtopng has seen any input and therefore before pnm-
topng has produced any output.
These are the kinds of format violations pamvalidate detects:
• A purported sample value exceeds the declared maxval.
• The stream ends prematurely.
This program works on multi-image streams, producing a corresponding
output stream.
See pamfix for a way to salvage an invalid Netpbm image stream.
OPTIONS
There are no command line options defined specifically for pamvalidate,
but it recognizes the options common to all programs based on libnetpbm
(See ]8;;index.html#commonoptions\ Common Options]8;;\ .)
SEE ALSO
pam(1) pnm(1) pamfix(1)
HISTORY
pamvalidate was new in Netpbm 10.66 (March 2014).
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/pamvalidate.html
netpbm documentation 22 March 2014 Pamvalidate User Manual(1)
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