Fast algorithm and implementation of 2-D discrete cosine transform

An algorithm for the fast computation of a 2-D discrete cosine transform (DCT) is presented. It is shown that the N×N DCT, where N=2^m, can be computed using only N 1-D DCTs and additions, instead of using 2N 1-D DCTs as in the conventional row-column approach. Hence the total number of multiplications for the proposed algorithm is only half of that required for the row-column approach and is also less than that of most of other fast algorithms, whereas the number of additions is almost comparable to that of others. It is also shown that only N /2 1-D DCT module are required for hardware parallel implementation of the proposed algorithm. Thus the number of actual multipliers being used is only a quarter of that required for the conventional approach