.TH PNGMETA 1 "10 March 1998"
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.\" Manual page for pngmeta - see end of page for copyright
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.\" $Source: /usr/local/cvsroot/png/pngmeta/pngmeta.1,v $
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.\" $Id: pngmeta.1,v 1.5 2001/05/16 14:46:52 cmdjb Exp $
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.SH NAME
pngmeta \- extract metadata from Portable Network Graphics (PNG) image files
.SH SYNOPSIS
.B pngmeta
.RB [ \-\-soif ]
.RB [ \-\-html ]
.RB [ \-\-xrdf ]
.RB [ \-\-all ]
.RB [ \-\-quiet ]
.RB [ \-\-uri\ URI ]
.RI [ filename ]
.SH DESCRIPTION
The
.I pngmeta
filter outputs the metadata from Portable Network Graphics (PNG)
format image files in one of these formats:
.LP
1. Simple key: value
.LP
2. SOIF format (as used by the Harvest system, version 1.4).
.IP
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.
.LP
3. HTML page
With each element as an element in a descriptive (DL) list
.LP
4. XML/RDF
With each element as an RDF property on the source URI.
.LP
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.
.SH FORMAT OPTIONS
.TP
.B \-\-soif
Format output using (Harvest) SOIF format.  This is the default if
the program is called PngImage.sum.
.TP
.B \-\-html
Format output in HTML, with each field/value as an element in a descriptive
.RB ( DL )
list.
.TP
.B \-\-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.
.SH OTHER OPTIONS
.TP
.B \-\-all
Output all the information about the image size, depth etc. even if
not usually printed.
.TP
.B \-\-quiet
Suppress the output of the banner for plain text output.
.B \-\-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.
.TP
.B \-\-help
Show a usage message
.TP
.B \-\-version
Show the program and library versions
.SH FILES
.TP 2.2i
.I pngmeta
executable
.SH "SEE ALSO"
.IR gif2png (1),
.IR libpng (3),
.IR pbm (1),
.IR pgm (1),
.IR pngcheck (1),
.IR pngtopnm (1),
.IR pnm (5),
.IR pnmgamma (1),
.IR pnmtopng (1),
.IR ptot (1),
.IR tiff2png (1),
.IR zlib (3)
.LP
For information about Harvest and its SOIF format:
.IP
http://harvest.cs.colorado.edu/
.LP
For
.IR PNG
.IP
http://www.libpng.org/pub/png/
.LP
For
.IR "libpng library"
.IP
http://www.libpng.org/pub/png/libpng.html
.br
http://libpng.sourceforge.net
.LP
For
.IR "zlib library"
.IP
http://www.zlib.net/
.IP
.SH AUTHORS
Version 1.11.
Dave Beckett, ILRT, University of Bristol, http://purl.org/net/dajobe/
.LP
The
.IR zlib (3)
library required by
.I pngmeta
is copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler.
.LP
Original UNIX manual page by R. P. C. Rodgers,
U.S. National Library of Medicine (rodgers@nlm.nih.gov).
.\" end of man page