ShapeLogic Scala is a generic computer vision library with cross-platform GUI in JavaFX. You write your image processing algorithm once, and it will work for images based on byte, short, float and double.
It has standard image processing algorithms like: Invert, threshold, edge detection, segmentation, skeletonize, edge tracer, vectorizer, point and line annotation all written in generic idiomatic Scala.
Scala is a very powerful programming language where you can do generic programming. I did have to use some quite sophisticated implicits to get it working.