Computer Science
ppmtoicr(1) ppmtoicr(1)
NAME
ppmtoicr - convert a portable pixmap into NCSA ICR format
SYNOPSIS
ppmtoicr [-windowname name] [-expand expand] [-display
display] [-rle] [ppmfile]
DESCRIPTION
Reads a portable pixmap file as input. Produces an NCSA
Telnet Interactive Color Raster graphic file as output.
If ppmfile is not supplied, ppmtoicr will read from stan-
dard input.
Interactive Color Raster (ICR) is a protocol for display-
ing raster graphics on workstation screens. The protocol
is implemented in NCSA Telnet for the Macintosh version
2.3. The ICR protocol shares characteristics of the Tek-
tronix graphics terminal emulation protocol. For example,
escape sequences are used to control the display.
ppmtoicr will output the appropriate sequences to create a
window of the dimensions of the input pixmap, create a
colormap of up to 256 colors on the display, then load the
picture data into the window.
Note that there is no icrtoppm tool - this transformation
is one way.
OPTIONS
-windownamename
Output will be displayed in name (Default is
to use ppmfile or "untitled" if standard
input is read.)
-expandexpand Output will be expanded on display by factor
expand (For example, a value of 2 will cause
four pixels to be displayed for every input
pixel.)
-displaydisplay
Output will be displayed on screen numbered
display
-rle Use run-length encoded format for display.
(This will nearly always result in a quicker
display, but may skew the colormap.)
EXAMPLES
To display a ppm file using the protocol:
ppmtoicr ppmfile
This will create a window named ppmfile on the display
with the correct dimensions for ppmfile, create and down-
load a colormap of up to 256 colors, and download the pic-
ture into the window. The same effect may be achieved by
the following sequence:
ppmtoicr ppmfile > filename
cat filename
To display a GIF file using the protocol in a window
titled after the input file, zoom the displayed image by a
factor of 2, and run-length encode the data:
giftoppm giffile | ppmtoicr -w giffile -r -e 2
BUGS
The protocol uses frequent fflush calls to speed up dis-
play. If the output is saved to a file for later display
via cat, drawing will be much slower. In either case,
increasing the Blocksize limit on the display will speed
up transmission substantially.
SEE ALSO
ppm(5)
NCSA Telnet for the Macintosh, University of Illinois at
Urbana-Champaign (1989)
AUTHOR
Copyright (C) 1990 by Kanthan Pillay (svpillay@Prince-
ton.EDU), Princeton University Computing and Information
Technology.
30 July 1990 1
Back to the index