ppmtoicr(1) General Commands Manual ppmtoicr(1)
ppmtoicr - convert a portable pixmap into NCSA ICR format
ppmtoicr [-windowname name] [-expand expand] [-display display] [-rle]
Reads a portable pixmap file as input. Produces an NCSA Telnet Inter-
active Color Raster graphic file as output. If ppmfile is not sup-
plied, 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 charac-
teristics 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 col-
ors on the display, then load the picture data into the window.
Note that there is no icrtoppm tool - this transformation is one way.
Output will be displayed in name (Default is to use ppm-
file 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 dis-
played for every input pixel.)
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
To display a ppm file using the protocol:
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
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
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 dis-
play will speed up transmission substantially.
NCSA Telnet for the Macintosh, University of Illinois at Urbana-Cham-
Copyright (C) 1990 by Kanthan Pillay (svpillay@Princeton.EDU), Prince-
ton University Computing and Information Technology.
30 July 1990 ppmtoicr(1)
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