High speed cosine transform

Abstract From the Canadian patent

Abstract, A discrete transform cosine circuit utilizing symmetries of the cosine matrix of coefficients to allow all multiplications to be done by "constant multipliers" comprising combinations of look-up tables and adders. Transform coefficients are developed by dividing each into a sequence of blocks of preselected size, the information in the blocks is sorted to develop a specific order and the reordered blocks are applied seriatim to a first one-dimensional cosine transform circuit employing the constant multipliers. The output of the first cosine transform circuit is applied to a transposing memory and then to a second cosine transform circuit that also employs "constant multipliers".