pnmtorle - Man Page

convert a Netpbm image file into an RLE image file.



[-h] [-v] [-a] [-o outfile] [pnmfile]


This program is part of Netpbm(1).

This program converts Netpbm image files into Utah RLE image files. You can include a transparency mask.  If the input is a multiple image file, the output consists of several concatenated RLE images.

The RLE file will contain either a three channel color image (24 bits) or a single channel grayscale image (8 bits) depending upon the pnm file depth.  If a converted ppm is displayed on an 8 bit display, the image must be dithered.  In order to produce a better looking image (on 8 bit displays), it is recommended that the image be quantizing (to 8 bit mapped color) prior to its display.  This may be done by piping the output of this program into the Utah mcut or rlequant utilities.  We show an example of this later.


In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common Options ), pnmtorle recognizes the following command line options:


This option will cause pnmtorle to operate in verbose mode.  The header information is written to "stderr".  Actually, there is not much header information stored in a Netpbm file, so this information is minimal.


This option allows the header of the Netpbm image to be dumped to "stderr" without converting the file.  It is equivalent to using the -v option except that no file conversion takes place.


This option causes pnmtorle to include an transparency channel in the output image.  The transparency channel is based on the image: Wherever a pixel is black, the corresponding trasparency value is transparent. Everywhere else, the transparency value is fully opaque.

-o outfile

If you specify this option, pnmtorle writes the output to this file.  If outfile is - or you don't specify -o, pnmtorle writes the output to Standard Output.


The name of the Netpbm image data file to be converted.  If not specified, standard input is assumed.


   pnmtorle -v file.ppm -o file.rle

While running in verbose mode, convert file.ppm to RLE format and store resulting data in file.rle.

   pnmtorle -h file.pgm

Dump the header information of the Netpbm file called file.pgm.

See Also



Wes Barris,
Army High Performance Computing Research Center (AHPCRC)
Minnesota Supercomputer Center, Inc.

Document Source

This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation is at

Referenced By


31 March 1994 netpbm documentation