I've created a simple android app that takes in 2 photos and tries its best to compare the 2. The app works fine when taking the pictures inside the app, but I'm having issues trying to load images from my phone. I want to be able to load pictures in that I've taken with my Camera and that are saved on my phone (specifically at
File file = new File(Environment.getExternalStorageDirectory(),imagePath);
Bitmap origBitmap = BitmapFactory.decodeFile(imagePath);
Since your target is API 25, you'll need to add in runtime persmission checks to access the user's media.
See this article for more information: https://developer.android.com/training/permissions/requesting.html
Alternatively, you can goto Android Settings->Apps and find your app and manually grant the app permission to media. This should get you passed your problem, but you'll want to add the runtime permission checks if you plan on distributing the app.