i typically use something like the following (using Image::Size) 
use Image::Size;

my ($w, $h) = imgsize("blort.jpg");
if ($w > 800) { my $f = $w / 800; $w = int($w/$f); $h = int($h/$f) };
if ($h > 600) { my $f = $h / 600; $w = int($w/$f); $h = int($h/$f) };

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In reply to Re: determining size of image by mreece
in thread determining size of image by Anonymous Monk

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