Two types of frequency characterization of the discrete cosine transform (DCT) have been analyzed in detail. One is performed in the natural spatial frequency domain and the other in the eigenspace of the firstorder Markov stationary random process. In the past the direct conversion from Fourier transform toDCT has been very difficult. It requires either doubling of the input data or reshuf fling the input data sequency. In this paper we have derived a unitary transform that allows one to directly convert a Fourier transform of natural sequence input into a DCT. Furthermore though it is known that the DCT asymptotically approaches the KarhunenLoeve transform (KLT) of the firstorder Markov stationary random process no exact relationship between these two transforms has been given. This paper derives the exact relation and exhibits the frequency characteristics of a DCT. Applications to image data compression and enhancement are also included.

Date Published: 1 November 1990
PDF: 12 pages
Proc. SPIE 1349, Applications of Digital Image Processing XIII, (1 November 1990); doi: 10.1117/12.23514

Published in SPIE Proceedings Vol. 1349:
Applications of Digital Image Processing XIII
Andrew G. Tescher, Editor(s)