ppmtoicr (1)
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.
"NCSA ICR"
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.
Macintosh
The ICR protocol shares
characteristics of the Tektronix graphics terminal emulation protocol.
Tektronix
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
-windowname name
Output will be displayed in
name
(Default is to use
ppmfile
or "untitled" if standard input is read.)
-expand expand
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.)
-display display
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 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:
giftoppm giffile | ppmtoicr -w giffile -r -e 2
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
AUTHOR
Copyright (C) 1990 by Kanthan Pillay (svpillay@Princeton.EDU),
Princeton University Computing and Information Technology.
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