Ipad Imported Pictures.

I use my i-pad to review photos downloaded from a camera SD card. These pictures appear in my Imported gallery. When ever I delete a photo from this gallery a copy of the same image I have downloaded onto a PC also is deleted.

How can I stop this?, I just want to delete the image from my i-pad imported gallery.

The PC that holds the photos of my camera also runs Itunes but not at the same time as any import. The same SD card is used to load the images onto the PC.