Hadamard transforms

The Hadamard transform and the Haar transform, to be considered in the next section, share a significant computational advantage over the previously considered DFT, DCT, and DST transforms. Their unitary matrices consist of and the transforms are computed via additions and subtractions only, with no multiplications being involved. Hence, for processors for which multiplication is a time-consuming operation a sustained saving is obtained. The Hadamard unitary matrix of order n is the matrix , generated by the following iteration rule: