Interpretation of eight-point discrete cosine and sine transforms as 33 orthogonal edge masks in terms of the FreiChen masks
33 edge masks have been commonly used for their simplicity. This paper presents an interpretation of the 8-point discrete cosine transform (DCT) and discrete sine transform (DST) as 33 orthogonal edge masks. The basis functions of the 8-point DCT and DST construct the 33 orthogonal DCT and DST masks that are closely related to the FreiChen masks.
freichen masks discrete cosine transform discrete sine transform compass gradient edge operators discrete fourier transform discrete hartley transform