Hello - you're new here and such brusque & terse questions do not help us to answer your requests; please provide more information: 1) What computer are you using, i.e. year; 2) What OS X is installed; 3) What iPad & iOS are in question; and 4) What type of photos reside on your iPad?
Just for starters, I'll give you one of multiple ways to achieve your goals, i.e. cable your iPad to the iMac and then open Image Capture (in Apps -> Other) - see if this works for you and let us know. Dave
For any future questions, you can read the thread linked to in my sig on how to make a good post. If you follow that guidance, you'll find we can generally get to the bottom of the problem pretty quickly.