Creating Photo Editing Extensions
Provide custom functionality in the Photos app by bundling an app extension.
Overview
You can incorporate your app’s features directly into the Photos app in iOS or macOS by building an app extension. A photo-editing app extension can enable people to edit media, apply your app’s filter effects, build slideshows, books, or custom content, such as a collage, right in Photos app using code that you supply.
Implement and bundle the app extension
Adopt the PHContentEditingController protocol to create an app extension that adds to the photo editing options and capabilities in the Photos app. Creating such an extension also requires using the following classes from the Photos framework:
PHContentEditingInput—To reference the photo or video to be edited
PHContentEditingOutput—To save the results of an edit
PHAdjustmentData—To describe an edit operation
Include the app extension in your app bundle and the system installs it in Photos at the same time someone installs your app.