Fixed-Pipeline Two-Dimensional Hadamard Transform Algorithms

In this correspondence, we first propose a new two-dimensional (2-D) Hadamard transform algorithm, which can be realized in fixed and identical pipeline stages. By introducing exchangeable permutations, the fixed-pipeline algorithm can be further extended to provide all 2-D lower-dimension transformations in intermediate pipeline stages. Finally, the parallel pipeline realization of the proposed algorithm is also suggested. For VLSI implementation, the proposed fixed-pipeline structure with the same computational complexity provides better modularity than the other famous algorithms. With lower dimension transformations, the proposed algorithm is suitable for applications in variable-block-size compression.