Rookie having problems with some filter code. Any help?


Hi folks.
As the subject line says, I'm a rookie when it comes to image
processing. I've stumbled onto a few resources online, most notably
Frederic Patin's paper titled "An Introduction to Digital Image
Processing" (available at
<http://www.gamedev.net/reference/programming/features/imageproc/> as of
the time I write this), and that's given me a lot of the background info
I need to hack together some basic image-handling routines, but I'm
having troubles with the results coming out of them - Quite possibly due
to the fact that I'm such a total greenhorn when it comes to writing
code to do digital image processing.

I'm not sure if the problems I'm having stem from me being so green at
the subject, one or more errors in Frederic's paper and/or example code,
artifacts of converting his code (originally written to target Windows
by way of a library called "Allegro 4.0") so it can run on a Macintosh,
my improperly "replacing" some of the Allegro routines with Mac-centric
versions, a combination of all these factors, or something completely
off the wall, but whatever the cause, it's clear to anyone taking even
the most casual glance at the results that my code is failing miserably.

The code in question (commented to the point of ridiculousness for this
post, since I haven't got a clue who might read it and wonder what on
earth it's trying to do) as well as a "raw" image and the results of
shoving that image through my attempt at a matrix-convolution based
sharpness filter, plus a link to Frederic's paper, can be seen here:
<http://www.sonic.net/~dakidd/Filterproblems.html>

If any of you have any suggestions for me as to how/why things are going
bad, and/or how to fix them, I'd be thrilled to death to hear from you,
either here on the group, or via email. (Just pay attention to my
anti-spam measures, as noted in my .sig, if you try to relpy to me via
email.)

I'd also welcome any pointers to more and/or better info on coding
digital image processing stuff, if anyone would care to point me in the
right direction. (Please... Spare me the "google it" - I've been wearing
out my eyeballs trying to figure out what is and isn't relevant in the
literally millions of results google hands me)

At this point, I just plain don't care how slow/inefficient/etc the code
I'm working with may be - I can worry about optimizing it later - AFTER
I've gotten it to the point where it's properly functional. I'm
currently MUCH more interested in getting basic correct functionality
out of it than any attempt at making it "the fastest, bestest, greatest
filter ever written".

Thanks in advance for any assistance you might be able to provide!

--
Don Bruder - dakidd@xxxxxxxxx - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
ever knowing it arrived. Sorry... <http://www.sonic.net/~dakidd> for more info
.

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