Connect your iPad to your computer and select it on the left-hand side of your computer's iTunes, and on the right-hand side there should be a series of tabs, one of which should be Photos. You will need to sync all the photos that you want on the iPad together in one go as only the most recent photo sync remains on the iPad - not including photos in a subsequent sync is how you delete photo from the iPad.
Besides what mentioned above, a article is about how to transfer iPad Photos onto computer.
Hopefully this works for all of you like it just worked for me!