xfer photos from IPod Touch(3gen) back into ITunes library in laptop.

I wish to copy/transfer my existing photos on my IPod Touch(3gen) into/onto the library of my ITunes acct, on my laptop. (windows 7). I have sync before but format prompts state that the current photos in the touch would be replaced by the ones in the library(in this situation there are none in the pc library). Usually this has deleted my photos in the touch. Any suggestions would be appreciated. Thank you in advance.