There should be a feature where the user can open the camera directly from the app, and take a picture of a document or a whiteboard if they are in class.
Then there should be a proccess similar to CamScanner, where the app attempts to automatically detect the borders of the page or the whiteboard, and clarifies text.

This should also be functional when importing photos, for tablets which don't have camera, or users who prefer to use their phones for pictures.