[plt-scheme] Digital camera files (plus a bug)

From: Eli Barzilay (eli at barzilay.org)
Date: Thu Jan 9 19:25:24 EST 2003

Anyone on this list who uses a digital camera (or just manages large
collection of EXIF-format jpg files) might find this useful: I wrote a
program that extracts EXIF information, all in Scheme.  It can be used
either as a module or as as a standalone script.  It's based on all
standard information I could put my hands on, so it is fairly
complete, the only thing that could be added is decoding brand-
specific information but this will not be a pleasant experience.

I've put the file at

  http://www.cs.cornell.edu/eli/tmp/exif.ss

if anyone wants to use this, please let me know (there's no
documentation about how this thing should be used).

Also, there is something strange that I've encountered.  I used to
open files (specified when running as a script) with a
`with-input-from-file', but for some reason this seemed to fill up the
memory.  Then I switched to openning and closing the file myself and
it worked better but still crashed.  Finally I resorted to an explicit
`collect-garbage' call and it looks like now it works fine with as
many files as I want.  In any case, it should definitely not crash
with a segmentation fault...  (I later found that this happens in an
irregular way so I can't reproduce reliably now but it does happen
after some good amount of files when I comment out the close-port and
GC...)

-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!


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