PSTOPNG 1 "07 April 2001" "Version 1.00"

Table of contents

• NAME
• SYNOPSIS
• DESCRIPTION
• OPTIONS
  • -crop
  • -debug
  • -extension
  • -gamma
  • -?
  • -help
  • -icon
  • -margin
  • -norun
  • -resolution
  • -version
  • -W
• SEE ALSO
• AUTHOR

NAME

SYNOPSIS

DESCRIPTION

For maximal color fidelity, bitmaps are produced in 24-bit color mode, with 16,777,216 possible colors.

The PNG format is an Internet Standard defined in RFC 2083 (1997), and major Web browsers, PostScript level 3 (1999), and picture editors such as gimp(1) photoshop(1), and xv(1) now support it.

Unlike the Compuserv GIF format, which uses the Lempel-Ziv-Welch (LZW) compression algorithm protected under U.S. Patent 4,558,302 (10-Dec-1985) held by Unisys Corporation, PNG is free of patent and copyright claims, and the PNG format is recommended for replacement of GIF images.

For each file given on the command line, an output file is written with the same basename as the input file, but with extension png, or the name specified by the -extension option.

With the -icon option, small companion files with the same name are also written in a subdirectory icons, which is created if necessary.

If no files are given on the command line, then stdin is read, and stdout is written, and no icon file can be produced.

pstopng is a convenient interface to gs(1), pngtopnm(1), pnmcrop(1), pnmmargin(1), and pnmtopng(1), which do the real work.

OPTIONS

To avoid confusion with options, if a filename begins with a hyphen, it must be disguised by a leading absolute or relative directory path, e.g. /tmp/-foo.eps or ./-foo.eps.

Options may begin with either UNIX-style single hyphens, or GNU/POSIX-style double hyphens, and may be abbreviated to any unique prefix.

-crop

Crop the image to remove edges that are the background color.

-debug

Turn on debug tracing.

-extension name

Replace the default output file extension, png, with name.

-gamma float-value

Specify an image gamma correction as a floating-point number. Small values darken the image, and large values lighten it. Typical values are in the range 0.5 .. 3.0.

[Default: 1.0]

-?

-help

Display a brief help message on stdout, and exit with a success status code (0 on UNIX).

-icon

Produce icon files as well as PNG files. An icon file is just a low-resolution (12dpi) bitmap that may be useful as a compact representation of what is in the PNG file.

In filter mode (no files on the command line), this option is ignored.

-margin pixels

Add a background margin of width pixels to the output image. This option is usually specified together with -crop.

-norun

Show on stdout the commands that would be executed, but do not run them.

Use this option to trap the complex command pipelines for further private customization.

-resolution dpi

Set the output bitmap resolution to dpi dots per inch.

[Default: 100 dpi, suitable only for screen resolution].

-version

Display program version numbers and dates on stdout, and exit with a success status code (0 on UNIX).

-Wcomponent,option

Pass option to the program component, which must be one of gs, pngtopnm, pnmcrop, pnmmargin, or pnmtopng.

This option, a POSIX convention, provides a general way for a user to pass options to programs invoked by another program. The value option is passed after any generated in response to options supplied to pstopng. For example, -Wpnmmargin,-black would cause any added margin to be colored black.

SEE ALSO

T. Boutell, RFC 2083: PNG (Portable Network Graphics) Specification Version 1.0, available at ftp://ftp.internic.net/rfc/rfc2083.txt.

John Miano, The programmer's guide to compressed image files: JPEG, PNG, GIF, XBM, BMP, Addison-Wesley Longman, Harlow, Essex, England 1999, ISBN 0-201-60443-4.

Greg Roelofs, PNG: The Definitive Guide, O'Reilly and Associates, Inc., Sebastopol, CA, Cambridge, MA, and Beijing, China, 1999, ISBN 1-56592-542-4.

AUTHOR

Nelson H. F. Beebe, Ph.D.
Center for Scientific Computing
University of Utah
Department of Mathematics, 322 INSCC
155 S 1400 E RM 233
Salt Lake City, UT 84112-0090
Tel: +1 801 581 5254
FAX: +1 801 585 1640, +1 801 581 4148
Email: beebe@math.utah.edu, beebe@acm.org,
       beebe@computer.org, beebe@ieee.org
WWW URL: http://www.math.utah.edu/~beebe