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Date:Mon Jan 8 23:47:00 2003 
Subject:New version of David Young's popvision library available 
From:Aaron Sloman 
Volume-ID:1030108.03 



David Young's popvision library comprises a set of teach files, help
files and libraries to provide support for:

    1.  teaching an introductory course in computer vision,

    2.  writing programs for research in computer vision.

    3.  Includes: displaying image files within a pop-11 X graphic
        window with a wide variety of display options
        The images can then be transformed in a number of ways
        using libraries provided. These are mostly C programs
        invoked from Pop-11, giving the advantage of speed that
        comes from C and the advantage of interactive development
        and testing that comes from Pop-11.

    4.  There are also libraries concerned with multi-layer perceptrons.

A more detailed overview is here:
    http://www.cs.bham.ac.uk/research/poplog/popvision/help/popvision
        18688 bytes

Originally the image display facilities in the popvision library were
restricted to 8 bit colour displays. About a year ago David extended the
display tools to handle 24 bit colour.

The basic display facilities deal with .ras files (in Sunraster format)
and other formats (e.g. .gif, .png, .jpeg) are handled by the 'convert'
utility which is distributed with some versions of linux (e.g. RedHat)
as part of the ImageMagick package.

Recently it was discovered that .ras files produced by 'convert' were
not displayed properly because red and blue bytes were not in the
expected order. The library for reading in such files has now been
modified to fix this.

The patch is provisional and has not been checked by David, but if you
wish to display 24 bit coloured images you should fetch either the whole
of the latest version of popvision or at least the library file that has
been changed. If your version of popvision is more than a month old,
fetch the whole package, to be safe:

The whole package is here:
    http://www.cs.bham.ac.uk/research/poplog/popvision.tar.gz
        2838586 bytes Jan  8 23:18

The modified version of sunrasterfile.p is here

    http://www.cs.bham.ac.uk/research/poplog/popvision/lib/sunrasterfile.p
        24324 bytes Jan  8 23:08

If you are a linux user and you have the 'convert' program installed
(included with RedHat) but not 'imconv', you are advised either to alter
this line:

    vars sunrasterfile_converter = "imconv";
 to
    vars sunrasterfile_converter = "convert";

or else include the latter line in any file that uses lib sunrasterfile.
(I don't know if imconv works on linux: I have never encountered it.)

More information on popvision:
An overview of the teaching materials in the package starts here
(David Young's vision course, at Sussex University):

    http://www.cogs.susx.ac.uk/users/davidy/teachvision/vision0.html

It should work with poplog on solaris+sparc, linux+pc, unix+alpha and
maybe also other linux/unix versions of poplog if any are still being
used.

Popvision is mostly compatible with rclib, though it was designed mainly
to work with the rc_graphic library. rclib is built on top of that and
most things that work with rc_graphic work with rclib also.

I should extend the examples here to include some popvision examples:
    http://www.cs.bham.ac.uk/research/poplog/figs/rclib/

Popvision is included in
    http://www.cs.bham.ac.uk/research/poplog/bham-linux-poplog.tar.gz
        21 Mbytes approx

If you already have poplog you can install popvision and other tar.gz
packages in the $poplocal/local/ directory using this script:

    http://www.cs.bham.ac.uk/research/poplog/com/install_package

Aaron
====
Aaron Sloman, ( http://www.cs.bham.ac.uk/~axs/ )
School of Computer Science, The University of Birmingham, B15 2TT, UK
EMAIL A.Sloman AT cs.bham.ac.uk   (ReadATas@please !)
PAPERS: http://www.cs.bham.ac.uk/research/cogaff/ (And free book on Philosophy of AI)
FREE TOOLS: http://www.cs.bham.ac.uk/research/poplog/freepoplog.html