Choosing a good Interpolating template is the key to better recover the subsampled image with low distortion. The All Phase Digital Filter is a new type of linear phase filter. According to All Phase theory
we propose 2-D Walsh interpolating template. Here a newmethod is applied: first diagonal interpolation
second horizontal interpolation and vertical interpolation. This algorithm has been compared with the nearest interpolation
bilinear interpolation
spline interpolation. Simulation results show this algorithm is with less computation complexity and can reduce the influences from noise.