Content-adaptive video up-scaling for high-definition displays

The introduction of HDTV asks for spatial up-conversion techniques enabling the display of standard resolution material. Recently, X. Li and M. Orchard proposed the 'New Edge-Directed Interpolation' (NEDI) algorithm for high quality up-scaling of natural images. We shall show that the method, although it generally behaves well, introduces annoying artifacts in fine-textured areas. Based on an analysis of these artifacts and taking advantage of the temporal correlation between video images, we propose an improved NEDI algorithm. In our evaluation, we compare the performance of the original and the improved NEDI method on a significant set of test images. We conclude from both subjective and objective measures that the proposed modifications improve the overall performance of NEDI.