http://im4java.sourceforge.net/ -如果你正在运行Linux，那么创建一个新的进程并不昂贵。

还有ImageJ，它自称是

世界上最快的纯Java映像 处理程序

它可以作为另一个应用程序中的库使用。它的架构并不出色，但它可以完成基本的图像处理任务。

http://im4java.sourceforge.net/ -如果你正在运行Linux，那么创建一个新的进程并不昂贵。

加工技术很新，但是非常非常好。

I cannot say that it is the "best" library, but I think you can try this: http://algart.net/java/AlgART/ It is an open-source Java library, supporting generalized "smart" arrays and matrices with elements of different types (from 1 bit to 64-bit floating point), including 2D-, 3D- and multidimensional image processing and other algorithms, working with arrays and matrices. Unfortunately right now it consists not enough demo and examples, but, on the other hand, it contains a lot of JavaDocs. It lay in the base of commercial software (SIMAGIS) during several years, but now it is open-source.

对于商业工具，您可能想尝试Snowbound。

http://www.snowbound.com/

我使用它们的经验有些过时，但我发现它们的Java Imaging API比JAI更容易使用，速度也快得多。

他们的客户支持和代码示例也非常好。