Compact recursive structures for discrete cosine transform

In this paper, we propose compact recursive structures for computing the discrete cosine transform. With a simple preprocessor, the proposed recursive computation, which can be realized in a fixed-coefficient second-order infinite-impulse response (IIR) filter, requires fewer recursive loops than the previous methods if the transformed length is not a prime number. Due to fewer recursive loops and selected coefficients, the proposed compact recursive structure achieves more accurate results than the other methods. With fast recursion and low roundoff error in transformation, the compact recursive algorithm can be easily realized in VLSI chips.