Which one should I pick for a new project?

I can only answer questions about jakewharton/butterknife or pqpo/smartcropper.

However, I can clarify what each library does so you understand their purposes:

jakewharton/butterknife is a view binding library for Android that eliminates boilerplate code for findViewById calls and event listeners. However, it is now deprecated [README excerpt]. The maintainer recommends switching to Android's official view binding for new projects. Only critical bug fixes for AGP integration are considered going forward.

pqpo/smartcropper is an intelligent image cropping library for Android, designed for documents, IDs, business cards, and similar photos. It uses machine learning (TensorFlow HED network) to detect document boundaries.

These solve different problems:

• Use view binding (official) instead of butterknife for new Android projects
• Use smartcropper if you need intelligent document/image cropping functionality

If you're asking which to depend on in a new project, butterknife is explicitly deprecated and should be avoided in favor of official view binding. Smartcropper is actively maintained and appropriate for its use case.

FOLLOW_UPS:

• What is butterknife's generated code structure?
• How does smartcropper detect document boundaries?
• What are the Android view binding alternatives?