Fast DCT-based spatial domain interpolation of blocks in images.

An efficient method is presented to restore a block in an image, using a reduced set of border pixels. The basic assumption is that, if the set of pixels consisting of the missing block and its border pixels is transformed by the DCT, the high frequency coefficients obtained can be set to zero. A system of linear equations results, whose solution yields approximations for the values of the lost pixels. In this interpolation scheme, only eight border pixels are used in the computation of any missing pixel. Simulation results show that the approach generally outperforms alternative methods at a smaller computational cost.