Your detective work probably found out what the issue might be. Yes, file size is the real culprit. In reality, the Android device can use an photo; even 2 Mb in size, with large dimensions, then it shrinks the image for display. The image size remains large and this is your issue.
Not knowing whether you display one or two or six photos at the same time, having too many images on display might be the issue or a single large file sized image may be cratering the app.
A simple method would be to discover the size of the image file about to be loaded into your app, if it is greater than a certain size, deny loading but I do not believe there is any way to check the file size using AI2 as there would be in Eclipse or Android Studio. You might be able to use a 'helper' app if you are a Java guy but that would be considerable work for an accomplished programmer to actually make the images smaller on the fly.
I expect the comments you made will be helpful to others experiencing a similar problem. I do not have a solution, but someone else might.
Regards,
Steve