I have a web application written in Java (Spring, Hibernate/JPA, Struts2) where users can upload images and store them in the file system. I would like to scale those images
The best tool for image editing is ImageMagick and it is open source.
There are two interfaces for the Java Language:
JMagick which uses JNI interface to ImageMagick
and
im4java what is a command line interface for ImageMagick