The release notes are here.
Here is my translation of them. Any corrections are welcome as my Japanese is a bit rusty!
Version 2.2.0 of the NyARToolkit has the following improvements:
1. Increased support for JMF Capture formats. The YUV camera output format is now supported. The toolkit now uses Java's colour space convertor for format change/translation.
2. Added angle properties to the NyARTransMatResult class. This allows you to calculate slope from a line.
1. The generic JMFCaptureClass has been replaced by a listing of particular devices or by a particular device. Please use the JmfCaptureDeviceList or JmfCaptureDevice classes instead of the JmfCameraCapture class.
2. Sub-class the NyARBufferReader_Reader_RGB24 class instead of using the previous JMF utility class.
1. I have fixed the problem with the Java3D input screen being reversed. The code where this was happening has been fixed.
The toolkit's overall processing time has been improved slightly.