This is an awesome (pure?) Java library I already used for some of my projects (e.g. for a Multi-JPG to PDF converter with book edge and finger detection). It o

This is an awesome (pure?) Java library I already used for some of my projects (e.g. for a Multi-JPG to PDF converter with book edge and finger detection). It offers basic things like thresholding, sharpening and edge detection as well as more complex stuff (video object tracking, etc.). It is pretty fast (although it is Java) and easy to use (well documented with examples). There is also a Demo android app in the play store, where you can take a good look at the features.