A new look at DCT-type transforms

A computationally efficient DCT- (discrete-cosine-transform) type orthogonal transform obtained by using a construction method developed by W. Kou and H. Zu (1986) is proposed. A recursive relation exists between a higher order and a lower order form of the kernel matrix of the transform and includes the DCT matrices as submatrices. The characteristics of the proposed transform and several fast transform algorithms are discussed. The proposed transform offers a higher computational efficiency than the traditional even discrete cosine transform and yields a mean-squared error close to that of the DCT. Since the HDCT has window spectral structures, it can be used in signal filtering and speech and image processing.<
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