[Accessibility_sig] making RTG PNG files accessible

[Jim Lyons]

This is my first post here, so hello.  My name is Jim Lyons and I work for
the Office of Telecommunication Services at UT Austin.  I have a
question about generating and presenting graphs that display network
traffic that are accessible.

In order to monitor network traffic, we use a program called RTG, a
third-party C program that generates graphs as PNG files.  These graphs
display network traffic from a variety of viewpoints.  They are very
useful to our customers and we provide our customers a variety of
different graphs of their network traffic, including graphs generated "on
the fly", displaying up-to-the-minute data.

Unfortunately, these PNG files are totally inaccessible. Also, since many
of them are generated "on the fly" it is not possible to have someone look
at the graph and write an interpretive description of it.

I was thinking that the best way to make these graphs accessible
programmatically would be to capture descriptive statistics and output
them to files that my PHP program could read and use either as alt text of
longdesc files.  But I'm not sure which descriptive stats would be best.
We could modify the code for RTG (not a pretty thought but doable) or
access the database ourselves with the same parameters sent to RTG, but
that would be prohibitively long for graphs covering long periods of time
(like a week or more).

Does anyone have any experience with this question?  I would appreciate
any helpyou might provide.

Thank you,

Jim Lyons


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Jim Lyons                     |  Operating Systems Specialist
OTS                           |  512-471-7414
University of Texas at Austin |  fax: 471-2449
jlyons at uts.cc.utexas.edu