Slingshot and image size on mobile

I have slingshot uploading images to S3. Starting to have a look at AWS Lambda to crop and resize.

How should I deal with images on mobile?

  1. Will mdg:camera let users pick from their own library (or take a photo)? Or is that a separate process?

  2. Do I let the user send any size, that can be big, or can you interact with Android or iOS and resize it before upload?