Discrete Cosine Transform

Authors

Nasir Ahmed, T. Natarajan, K. R. Rao

Year

1974

Journal Paper

Algorithm

Discrete Cosine Transform

Source

IEEE Transactions on Computers

Identifiers

DOI 10.1109/T-C.1974.223784

Abstract¶

A discrete cosine transform (DCT) is defined and an algorithm to compute it using the fast Fourier transform is developed. It is shown that the discrete cosine transform can be used in the area of digital processing for the purposes of pattern recognition and Wiener filtering. Its performance is compared with that of a class of orthogonal transforms and is found to compare closely to that of the Karhunen-Loeve transform, which is known to be optimal. The performances of the Karhunen-Loeve and discrete cosine transforms are also found to compare closely with respect to the rate-distortion criterion.

Summary¶

Ahmed, Natarajan, and Rao introduce the DCT as a real orthogonal transform with fast computation and near-Karhunen-Loeve energy compaction for correlated signals. Its practical combination of decorrelation, compact basis functions, and efficient implementation made it central to transform coding and later to JPEG and many video standards.