[EMAIL PROTECTED] on wrote...
| > I *think* that thumbnail never loads the entire image into memory,
|
| Right. It most likely subsamples each scanline and therefore substantially
| reduces the memory requirement. We could do the same in ImageMagick like we
| already do for JPEG:
|
| convert -size 600x800 image.jpg -thumbnail 600x800 thumbnail.jpg
|
| Its just something we have not implemented yet.
However....
1/ the -size to JPEG read is only a hint. Typically you will get an
image that fits into the next power of two size.
Eg 1024x1024
2/ Sub-sampling is not a good image reduction technique as it does not
provide a good selection of pixels to merge. It is recommened that
you read an image at least twice the size of the final thumbnail
to get a good thumbnail result.
This is talked about in IM Examples on Thumbnails
http://www.imagemagick.org/Usage/thumbnails/
3/ The "thumbnail" program probably does not generate good thumbnails
but horible 'smalpled' thumbnails. IM produces a "quality" result.
Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]>
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Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/
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