Which one should I pick for a new project?

I can only recommend based on what these repositories are designed for—they solve completely different problems:

baseflow/photoview is an Android library for image viewing with zoom/pan gestures. Use it if you need:

• Multi-touch zooming and double-tap zoom in Android apps
• Smooth scrolling and fling gestures
• Integration with ViewPager or similar scrolling parents
• A lightweight, specialized image viewer component

knowm/xchange is a cryptocurrency exchange API abstraction library for Java. Use it if you need:

• Unified access to multiple crypto exchange APIs (Bibox, Ascendex, etc.)
• Market data (tickers, order books, trades)
• Account management and trading functionality
• Both REST and WebSocket/streaming APIs

Critical caveat: The RepoPilot analysis flags baseflow/photoview as STALE — last commit 4 years ago. This is a significant risk for a new project. The library may have unpatched security issues, may not work with recent Android API levels, and won't receive maintenance.

For a new project, I'd recommend:

• photoview: Only if you have no other options and can commit to maintaining a fork yourself
• xchange: More actively maintained (no staleness flag), but verify current activity in the actual repo before depending on it

What problem are you trying to solve? That will determine which (if either) is appropriate.

FOLLOW_UPS:

• What Android API versions must your app support?
• Are you building a crypto trading application or image viewer?
• Can you maintain a forked library if needed?