Two dimensional interpolation of real sequences using the DCT

The conventional discrete cosine transform (DCT) is used to perform two-dimensional (2-D) interpolation of real sequences. It is shown that with a suitable modification of the DCT multiplying coefficients, alias-free image interpolation is achieved. The algorithm is suitable for video signal decimation and interpolation. The normalised mean square error decreases as the size of the interpolated sequence increases. Accurate image interpolation without aliasing, blocking or snowing is achieved. Extension of the algorithm to three and higher dimensions is given.