> That seems kind of absurd.... Is the structure of the TIFF file really
> such that the image must be loaded into memory as a whole or something?!
>
> I've had good success with converting (including size conversion)
> between other image formats on a roughly scanline-by-scanline basis,
> which allows absolutely huge images to be converted with no memory
> problems. [I'm writing my own software though; I don't know which other
> packages do this.]
Something is definitely fishy with the way 'convert' works. It
couldn't handle a 117MB image on a machine with ~ 500MB of memory.
That's not right! It should have been to do the conversion and resize
a few rows at a time, without a lot of memory, but nyet.
After examining the smaller of the two GIFs, I found it had problems--
black pixels in areas where they obviously didn't belong-- obvious
being the key word, it didn't look good. Since I had the 174MB PBM on
my local machine now (uncompressed from the 40MB bz2), thought I'd
give the Gimp a try.
Worked like a champ! No problems loading the image, resizing,
converting to indexed, or writing as GIF. Much, much faster than
convert with no painful thra****ng and trauma, and more im****tantly,
the final result was better: no obvious defects. So, I re-did the
larger of the two GIFs with the Gimp and it came out smaller (13MB
instead of convert's 15.5MB) and looked as good. Note I had dithering
turned off for both of these, which makes a large difference in the
final GIF size, and result looked better IMO.
--ian
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