PNGMETA(1)						      General Commands Manual							PNGMETA(1)

NAME

       pngmeta - extract metadata from Portable Network Graphics (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 PngImage.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 XMLRDFDATA field is found, it is assumed to be RDF/XML content and is emitted in a second rdf:Description 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), pngtopnm(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 library

	      http://www.zlib.net/

AUTHORS

       Version 1.11.  Dave Beckett, ILRT, University of Bristol, http://purl.org/net/dajobe/

       The zlib(3) library required by pngmeta is copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler.

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

								   10 March 1998							PNGMETA(1)