Design and implementation of a novel linear-array DCT/IDCT processor with complexity of order log2 N

A new linear-array architecture for computation of both the discrete cosine transform (DCT) and the inverse DCT (IDCT) is derived from the heterogeneous dependence graphs representing the factorised coefficient matrices in the matrix formulation of the recursive algorithm. Using the Kronecker product representation of the order-recursive algorithm, it is observed that the kernel operations of the DCT and IDCT can be merged together by proper input/output data reordering. The processor containing only O(log/sub 2/N) stages is fully pipelineable and easily scaleable to compute longer DCT/IDCTs with transform length N to the power of two. Owing to the systematic matrix formulation and the corresponding efficient architectural design, the new DCT/IDCT processor has the advantages of high-throughput rate and low hardware cost. Furthermore, the power consumption can be reduced significantly by turning off the operation of the arithmetic units whenever possible.