Radix-2 algorithm for the fast computation of type-III 3-D discrete W transform

In this letter, an efficient algorithm for three-dimensional (3-D) vector radix decimation in frequency is derived for computing the type-III 3-D discrete W transform (DWT). Comparison of the computational complexity with the familiar row–column algorithm shows that the proposed approach reduces significantly the number of arithmetic operations. Moreover, the proposed method has very regular structure, thus, it is easy to implement.