A subpixel algorithm using interpolation method based on normal direction GONG Li WANG Zhong LI Chao

摘要

As one branch of subpixel technology, curve interpolation method is the most popular for its higher precision and lesscomplexity. But the method has longer running time and bigger direction error, since it makes use of convolutionbetween direction templates and pixel gray values to get Gradient direction which is interpolating direction. So a newmethod is proposed in which unisometric cubic spline interpolation is operated along the normal direction of theedge-point. It illustrates not only how to choose sampling points for interpolation, but also how to figure node values ofthose points, then establishes the suitable interpolating boundary conditions. The method reduces not only the uncertaintybut also the runtime to 1/2, and improves measuring precision and efficiency.