If you have a recent backup of the iPad in iTunes (it creates one of these every time you sync), there are several programs on the net that promise to extract the photos from that backup.
I've never used one of these, I have not researched anything about their reliability, or the trust worthiness of the various developers, so do your own research and proceed with due caution.
I got quite a few hits Googling "recover photos from iPad backup".
The other option is to Restore from Backup to your iPad in iTunes. Since this is the same source of pictures, I'm thinking the programs would be the safer (less likely to lose other iPad content) way to go.
If the photos are not in your backup, then (to the best of my knowledge) there is no way to recover them.