Image enlargement via interpolatory subdivision

A novel image enlargement method based on a modified interpolatory subdivision scheme is proposed in this study. The subdivision scheme is a modification from the 4-point interpolatory subdivision by substituting the interpolation rule for a tangent-constrained Hermite interpolation and in surface case the subdivision is derived from a Ferguson patch. By estimating the gradients of the Ferguson patch, the authors present an image enlargement algorithm preserving the sharp edges. Benefit from the advantages of subdivision, this algorithm runs fast. Numerical experiments illustrate the efficiency of the novel method.