As far as I know 5.4 is still not truly multilingual. Neither for images nor documents, While you can have different titles you can only have on document/image.
I know it sad and makes it kind of useless.
This is from December 2011 http://www.sitefinity.com/developer-network/forums/general-discussions-/content-libraries-and-multiple-languages
There isn't such a PITS issue logged. We currently do not plan to implement multilingual libraries the way that you mention. Apologies for the inconvenience.
I did not find a PITS where you could vote.
Bottom line - unless I am mistaken you will not see this happen anytime soon.
Telerik goes the big company enterprise way. I wonder how the big companies are handling this. I guess just have two libraries one for french and one for english.
PS: Telerik if I am wrong, sorry - Have no 5.4 mulitlingual project yet.
PITS would still be nice.