The paper shows that the type-II r-dimensional discrete cosine transform (r
D-DCT-II) of size q(l1) x q(l2) x...x q(lr), where r > 1 and q is an odd pr
ime number, call be converted into a series of one-dimensional reduced DCT-
IIs by using the polynomial transform. The number of multiplications for co
mputing an rD-DCT-II is significantly reduced compared to that needed by th
e row-column method. The total number of arithmetic operations (additions p
lus multiplications) needed by the proposed algorithm is also reduced subst
antially. In addition to the capability of dealing with different dimension
al sizes, the proposed algorithm also has a simple computational structure
because it requires only the 1D-DCT-II and the polynomial transform.