ZoomLayout
2D zoom and pan behavior for View hierarchies, images, video streams
A collection of Android components that support zooming and panning of View hierarchies, images, video streams, and much more. In fact, ZoomLayout, ZoomImageView and ZoomSurfaceView are just very simple implementations of the internal ZoomEngine. The Zoom engine lets you animate everything through constant updates, as long as you feed it with touch events, with a Matrix-based mechanism that makes it very flexible.