Your code is replacing the number with the md5 of that number, which is a poor idea.

My suggestion was that you replace the number with the md5 of the files contents. Something like: 

my $file = 'joe_34455667.jpg';
my $md5 = md5_hex( do{ local( @ARGV, $/) = $file; <> } );
$file =~ s[_(\d+)\.jpg$][_$md5.jpg];

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In reply to Re^3: Renaming an image file by BrowserUk
in thread Renaming an image file by Anonymous Monk

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