PD Image Processing Software for Suns

Thu Mar 9 08:49:02 AEST 1989

This is to introduce a toolkit of image processing programs, collectively
called the ALV toolkit for historical reasons, written by Phill Everson
<everson at uk.ac.bris.cs> in the Computer Science Dept. of Bristol
University, United Kingdom.

The toolkit is designed to aid image processing work on Sun workstations.
It is intended to be easy to use, though not restrictive to experienced
users, user-configurable, extensible and flexible.  For example the
toolkit will work on both black and white and colour workstations and in
either case will transparently, to the user, display an image to the best
of its ability on the screen.

The toolkit has recently been rewritten to use the standard Sun rasterfile
format to store its images allowing multiple depth images to be processed
by the same toolkit and easy migration of data between packages.

*** All people currently on the alv-users mailing list will receive a copy
of the new toolkit in the next couple of days.

The toolkit is made up of a number of tools.  These include programs to
display an image on the screen, to display a histogram, to perform
histogram equalisation, to threshold, to print an image on an Apple
Laserwriter, to invert an image and to convolve an image with a
user-supplied linear filter.  Currently, there are 27 such programs.

The toolkit was initially written to fulfill a need at Bristol University
for a single coherent set of tools to support basic image processing
research on a variety of projects.  We had found that each user or group
of users was writing their own copy of programs to do similar things, like
displaying an image on the screen, and more importantly, in an enviroment
were disk space is always at a premium, was each keeping separate copies
of these often large programs.

Using a coherent set of tools with a consistent file format has
substantially increased cross-project communication and in addition has
provided a higher starting point on the learning curve for novice
Sun-Users/Imagers. We have found that users generally use the core tools
as a basis and are then able to concentrate their work in their own area
of interest.

The ALV toolkit comes complete with a 40-50 page manual online which can
easily be dumped to a laserwriter to provide and impressive reference for
a Public Domain Program.

The toolkit is currently distributed via email.
Contact <alv-users-request at uk.ac.bris.cs> to request a copy.

The following are the commands currently in the toolkit:

     array2ras - convert array to raster
     blend - blend two rasters together
     box - box a raster
     convert - convert textual raster to raster
     convolve - convolve a raster with a linear filter
     dither - convert 8 bit raster to 1 bit using dither matrix
     dsp  - display a raster on screen
     equalise - equalise a raster
     ffill - flood fill a raster
     halftone - convert an 8 bit raster to  1  bit  using  bitmap
     font
     hist - display histogram of raster
     im2ras - convert old ALV format to raster
     invert - invert the pixels in a raster
     ras2array - convert raster to array
     ras2im - convert raster to old ALV format
     ras2lw - output a raster on a Laserwriter
     rasinfo - print raster udimensions and depth
     rasrange - range a raster's greylevels
     rasregion - clip a raster to a region
     rasscale - scale a raster's size by a scaling-factor
     rasthresh - threshold raster
     rasval - print pixel values of raster
     scr2ras - interactive screendump to raster
     transform - shear or rotate a raster
     winlev - convert N bit deep raster to 8 bits deep
     winlev8  -  interactively  change  window  and  level  of  a
     displayed raster

Phill Everson

SNAIL:     Phill Everson, Dept Comp Sci, University of Bristol, England
JANET:     everson at uk.ac.bris.cs
UUCP:      ...mcvax!ukc!csisles!everson
ARPANET:   everson at cs.bris.ac.uk OR everson%uk.ac.bris.cs at nss.cs.ucl.ac.uk
BITNET:    everson%uk.ac.bris.cs at ukacrl.bitnet