Fast discrete cosine transform pruning

A new fast pruning algorithm is proposed for computing the N₀ lowest frequency components of a length-N discrete cosine transform, where N₀ is any integer less than or equal to N, and N=2^m. The computational complexity of the developed algorithm is lower than any of the existing algorithms, resulting in significant time savings. In the special case that N₀=2^m0, the required number of multiplications and additions is ½m₀N and (m₀+1)N+(½m ₀-2)N₀+1, respectively