Image coding using adaptive-blocksize Princen-Bradley transform

This paper describes the extension of Princen-Bradley transform, or MDCT, to a variable blocksize case and its application to image coding. An adaptive window scheme is also introduced and window shape selection mechanism is carefully considered. By introducing an adaptive blocksize and adaptive window scheme into MDCT image coding, the coding efficiency has been improved while maintaining the same high subjective image quality of MDCT coding. General conditions for perfect signal reconstruction of adaptive blocksize MDCT are mathematically derived in the appendix.