PNGMETA(1)                                           PNGMETA(1)





NAME
       pngmeta  - extract metadata from Portable Network Graph-
       ics (PNG) image files

SYNOPSIS
       pngmeta [--soif]  [--html]  [--xrdf]  [--all]  [--quiet]
       [--uri URI] [filename]

DESCRIPTION
       The  pngmeta  filter  outputs the metadata from Portable
       Network Graphics (PNG) format  image  files  in  one  of
       these formats:

       1. Simple key: value

       2.  SOIF  format (as used by the Harvest system, version
       1.4).

              As such it can be used as a  Summarizer  for  the
              Harvest Essence system.  It could also be used by
              other indexers to extract data for  indexing  PNG
              images.

       3.  HTML  page  With  each  element  as  an element in a
       descriptive (DL) list

       4. XML/RDF With each element as an RDF property  on  the
       source URI.

       In  the  absence  of  options, the program operates as a
       filter, accepting input from stdin and sending output to
       stdout.   If  a single file name is given, it is assumed
       to correspond to a PNG file, and is processed.

FORMAT OPTIONS
       --soif Format output using (Harvest) SOIF format.   This
              is  the  default  if the program is called PngIm-
              age.sum.

       --html Format output in HTML, with each  field/value  as
              an element in a descriptive (DL) list.

       --xrdf Format  output  in RDF/XML, with each field/value
              as an element in an rdf:Description block  inside
              the outer rdf:RDF wrapper element.  If an XMLRDF-
              DATA field is found, it is assumed to be  RDF/XML
              content  and  is emitted in a second rdf:Descrip-
              tion block.

OTHER OPTIONS
       --all  Output all the information about the image  size,
              depth etc. even if not usually printed.

       --quiet
              Suppress  the output of the banner for plain text
              output.  --uri URI Set the URI that is  used  for
              the  SOIF  and  XML/RDF outputs.  By default this
              will be the filename, or "stdin" if this  is  the
              program is used as a filter.

       --help Show a usage message

       --version
              Show the program and library versions

FILES
       pngmeta               executable

SEE ALSO
       gif2png(1), libpng(3), pbm(1), pgm(1), pngcheck(1), png-
       topnm(1),  pnm(5),  pnmgamma(1),  pnmtopng(1),  ptot(1),
       tiff2png(1), zlib(3)

       For information about Harvest and its SOIF format:

              http://harvest.cs.colorado.edu/

       For PNG

              http://www.libpng.org/pub/png/

       For libpng library:

              http://www.libpng.org/pub/png/libpng.html
              http://libpng.sourceforge.net

       For zlib-zlib library

              http://www.info-zip.org/pub/infozip/zlib/
              http://www.mirror.ac.uk/sites/ftp.freesoft-
              ware.com/pub/infozip/zlib/


AUTHORS
       Version 1.10.  Dave Beckett, ILRT, University  of  Bris-
       tol, http://purl.org/net/dajobe/

       The zlib(3) library required by pngmeta is copyright (C)
       1995-1996 Jean-loup Gailly and Mark  Adler.   Some  code
       was  modified  from  the  code for the libpng(3) library
       function png_read_end() which is copyright (c) Guy  Eric
       Schalnat, Andreas Dilger, Glenn Randers-Pehrson and oth-
       ers -- see the source for details.

       Original UNIX manual page by  R.  P.  C.  Rodgers,  U.S.
       National Library of Medicine (rodgers@nlm.nih.gov).



                         10 March 1998               PNGMETA(1)
