Unfortunately, the only way i've found this functionality is through the app Skitch. You'll have to first download the app from the Play Store. Once downloaded, you open the gallery, select the photo you want to annotate, and then select the share button. You will be given be given some options and you'll want to select Skitch.
Skitch will open with the photo you selected and you can then annotate the photo using your s-pen. I must warn you that the writing doesn't seem as fluid as I'd like, but for quick markups on photos it's the best solution I've found so far.
On the Note 5.3 phone Samsung made it easy, but on the tablet it seems to require a third party app
Sent from my GT-N8013 using Android Central Forums