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 Output, 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 pnmtopng 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
        Common Options ⟨index.html#commonoptions⟩ .)

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