ImageResize4J is a Java class library developed by Gif4J Software for high-quality image resize and scaling. It offers 24 interpolation filters included such well-known as Bilinear, Bicubic, Lanczos3 or Hamming and some unique interpolation filter families such as Ideal or Sharp. ImageResize4J is the most powerful and comprehensive solution for professional Java-based image processing services such as online photo publishing, mobile content management etc.
The library is 100% pure java (no native code) and compatible with Java 1.2 and later.

Java2D, Adobe Photoshop and ImageResize4J image resize comparison (Source photo has been resized to 150x106 thumbnails)
Java2D Bicubic (code)	Adobe Photoshop Bicubic	IR4J Sharp Light 5 (code)

ImageResize4J also offers high-quality image resize and scaling for JAI-based solutions:

"Scale" JAI Operation and ImageResize4J "ImprovedScale" JAI Operation comparison (Source photo has been resized to width=162px maintaining the aspect ratio)
JAI "Scale" Bicubic (code) - erroneous black bottom line	IR4J "ImprovedScale" Sharp Light 5 (code)