A Unified Algorithm for Subband-Based Discrete Cosine Transform

Abstract EN

Discrete cosine transform (DCT) and inverse DCT (IDCT) have been widely used in many image processing systems and real-time computation of nonlinear time series.

In this paper, the unified DCT/IDCT algorithm based on the subband decompositions of a signal is proposed.

It is derived from the data flow of subband decompositions with factorized coefficient matrices in a recursive manner.

The proposed algorithm only requires (4(log2n)−1−1) and (4(log2n)−1−1)/3 multiplication time for n-point DCT and IDCT, with a single multiplier and a single processor, respectively.

Moreover, the peak signal-to-noise ratio (PSNR) of the proposed algorithm outperforms the conventional DCT/IDCT.

As a result, the subband-based approach to DCT/IDCT is preferable to the conventional approach in terms of computational complexity and system performance.

The proposed reconfigurable architecture of linear array DCT/IDCT processor has been implemented by FPGA.