High quality image enlargement based on 0-degree B-spline

A simple and feasible image enlargement method is presented. It is based on orthogonal projection theory and adopts 0-degree B-spline as analysis and synthesis function. In addition, a prefilter is introduced whose impulse response is the convolution inverse of 0-degree B-spline function to maintain the high frequency components of images. The prefilter simplifies the projection based method and reduces the computational burden. Experiments on standard images show that our method provides sharper enlargement images and it is faster than the conventional projection based methods.