Thread: thumbnail sizes
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Old January 7th 18, 11:30 PM posted to rec.photo.digital
Mayayana
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Posts: 1,514
Default thumbnail sizes

"Phillip Helbig (undress to reply)" wrote

| I've been using this to make thumbnails of jpeg files:
|
| for img in *.JPG; do
| echo thumbnailing $img
| convert -geometry 105x70 $img $img
| done
|
| Files from the K10D result in thumbnails of about 57 kB and those from
| the GR of about 46 kB, with little variation. Is there a simple
| explanation as to why?
|
| The K10D is 10 megapixels and the GR 16, but I don't see why that is
| relevant here, but maybe I am missing something.
|

Are the originals the same aspect ratio?
If not then you might be getting something
like a 105x65 and a 105x50. You also didn't
spec the compression level with the quality
parameter. (Assuming you're using ImageMagick
as Carlos speculated.)

You didn't say what the context of the code
is. You didn't say why you're making thumbnails
or whether they need to be the same size. You
didn't extract them, which would probably make
more sense. So all we know is that you're making
thumbnails with a poorly suited tool and you don't
much care about the quality of them. But you
do care about the file size? Why?

It'd be easier for people to provide a helpful
answer if you'd explain yourself. We're not your
mother.