iPhoto 5 import question?

[liketom]

i have backed up my old iphoto 4 collection on external HDD - my old albums have been through iPhoto 4 many times being resized modded ect..
Question is i have over 15,000 photo's on there many of them duplicates is there a way of only importing file sizes/or resolutions only

i could use the finder to find files over the size of ... but i have a mixed bag of photo's many taken on 4mp cam some on my old mobile phone

any help?