ppmtoicr
convert a portable pixmap into NCSA ICR format
Synopsis
ppmtoicr
[-windowname name] [-expand
expand] [-display display]
[-rle] [ppmfile]
add an example, a script, a trick and tips
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
download a colormap of up to 256 colors, and download the picture
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:
giftopnm giffile | ppmtoicr -w giffile -r -e 2
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 standard input.
Interactive
Color Raster (ICR) is a protocol for displaying 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 Tektronix 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.)
bugs
The protocol
uses frequent fflush calls to speed up display. 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
NCSA Telnet
for the Macintosh, University of Illinois at
Urbana-Champaign (1989)
author
Copyright (C)
1990 by Kanthan Pillay (svpillay[:at:]Princeton[:dot:]EDU), Princeton
University Computing and Information Technology.