[quote="leo"]You could do this in Opus by "abusing" the Rename Script feature. Rename Scripts can be written in VBScript (and Perl, etc.) and can be passed information like the image width or height. A script can do whatever it likes with the information passed to it and can choose not to actually rename any of the files.
Maybe it's strange to use Rename command to do something that isn't renaming, but it will work. 
[/quote]
I've turned my idea into a real example:
Copy IMG links to Clipboard with Width and Height
I've also written a separate post which explains the technique in detail with a simplified example:
"Abusing" Rename Scripts to do other things with file info
Enjoy!