peterson@utah-cs.UUCP (02/25/87)
A few months ago there was quite a bit of discussion about image raster image
formats and compression on comp.graphics. A month or so ago Spencer
hinted that we would be releasing the Utah Raster Toolkit, which helps solve
many of these problems. Here's the complete announcement.
Cheers,
jp
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THE UTAH RASTER TOOLKIT
The Utah Raster toolkit is a collection of programs and C routines for
dealing with raster images commonly encountered in computer graphics. It
provides the following major functions:
* A device and system independent image format for storing images
and information about them. Called the RLE format, it uses
run length encoding to reduce storage space for most images.
* A library of C routines for reading, writing and manipulating
images stored in the RLE format.
* A collections of programs for manipulating and displaying RLE
images.
The Format:
The device independent RLE file has two parts, the header, which stores
information about the image (size, position, channel information,
color maps, comments, etc), and the actual image data in a run length
encoded format. The RLE format often requires about a third of the
available space for most "image synthesis" style images. If the image
does not compress well, the RLE format stores it as straight pixel data
with little extra overhead. The format has been developed over the past
five years at Utah.
The Library:
C routines are provided for setting up and reading the image header,
and for reading and writing the image a scanline at a time. Images can
be read or written using two different methods. Using the "row" method,
the library performs the RLE encoding and decoding. With the "raw" method,
scanlines are constructed directly with RLE opcodes. Additional routines
are available for generating dither matrices (e.g., for display programs
running on devices with less than 24 bits of color).
The Tools:
comp - Digital image compositor. Provides the operations over, atop,
in, out, xor, plus, minus and diff on two images.
crop - Crop an image
repos - Change the position in the RLE header
avg4 - Downfilter an image by 1/4, generating a matte channel if one
didn't previously exist.
fant - Rotate and/or scale in image by an arbitrary (float) value.
smush - Perform a simple Gaussian filter on an image
rlehdr - Dump the contents of the RLE header in human readable form
rlesetbg - Set the background color stored in the RLE header
rleaddcom - Add a comment to the RLE file's header
rleswap - Swap, copy or delete channels in an RLE file
rlebg - Generate a solid or variable background
rleflip - Rotate an image by 90/180 degree increments
rleldmap - Load a color map into an RLE file from a variety of sources
applymap - Apply color map values to pixel values
rlesetbg - Set the background color in the RLE header
painttorle - Convert MacPaint files to RLE format.
rletopaint - Convert RLE files to MacPaint
rletops - Convert an RLE image to PostScript (graylevel)
smush - Defocus an image with Gaussian convolution
to8 - Convert a 24 bit RGB image to an eight bit dithered one
tobw - Convert 24 bits to 8 bits black and white
Display programs are provided for:
getap - Apollo workstation...
getcx3d - Chromatics CX1500 display
getfb - BRL "libfb" displays
getgmr - Grinnell GMR-27 (remember those?)
getX - Workstations running the X window system
getmex - Iris running Mex
getiris - Iris in raw 24 bit mode.
- [Note display programs for a particular device are
simple to add]
All the tools are designed to pipe together, so they can be used as
filters on images much like the standard Unix tools filter text.
Plus:
The raster toolkit also includes Unix man pages for the library and
commands, some sample images, and additional documentation.
System Requirements:
We have successfully ported the Raster Toolkit to a number of Unix
systems, including 4.2/4.3bsd (Vax, Sun, etc), Apollo Domain/IX, HP
Series 3000, SGI Iris, Gould UTX. Display programs are included for
several devices. Creating display programs for additional devices is
a straightforward task.
Distribution:
For ARPAnet sites, the toolkit may be obtained via anonymous FTP to the
site utah-cs, in the file pub/toolkit.tar. Sites not on the ARPAnet can
obtain the Raster Toolkit on a 9-track, 1600 bpi tar format tape by
sending check or money order for $200.00 to:
Attn: Utah Raster Toolkit, Loretta Cruse
Department of Computer Science
University of Utah
Salt Lake City, UT, 84112
Courtesy Mike Muuss at BRL, the Raster Toolkit is also included as
contributed software in the BRL-CAD distribution.
Although the Raster Toolkit software is copyrighted, it may be freely
re-distributed on a "GNU-like" basis.
For further technical information on the Raster Toolkit, send mail
to:
toolkit@cs.utah.edu (ARPA)
{ihnp4,decvax}!utah-cs!toolkit (UUCP)thomas@spline.UUCP (02/25/87)
A small correction/addition to this announcement: Checks should be
made payable to the Department of Computer Science if you are ordering
a tape.
=Spencer ({ihnp4,decvax}!utah-cs!thomas, thomas@utah-cs.ARPA)thomas@spline.UUCP (02/26/87)
We seem to have gotten bit by the Arpanet domain transition. If you
can't find utah-cs in your host table, try cs.utah.edu, or (in cases of
extreme frustration) 10.0.0.4. Sorry about that.
=Spencer ({ihnp4,decvax}!utah-cs!thomas, thomas@utah-cs.ARPA)