Currently building a bot for Facebook Messenger that allows users to send us an image which we then process. We've got it working and images sent via Messenger.com are good enough quality for what we need. Unfortunately when a user sends us an image via the Messenger app on their phone the image is compressed and greatly reduced in size. An image taken with my iPhone camera and sent through the iPhone Messenger app ends up being about 500 pixels wide which isn't really big enough for our needs.
Does anyone know of a way to access a large image using the Messenger API? It all depends, I guess, on whether Facebook is processing the image on the phone to speed upload time.
It'd be shame to have to direct users to a web page to upload.
Unfortunately the Messenger Platform API is limited by how the Messenger app handles images in this case. On Android high-res images can be uploaded for the app, but it isn't in iOS.