Image enlargement using bi-directional shifted linear interpolation

In this work, we propose a new image enlargement method using bi-directional shifted linear interpolation. Based on two interpolation functions defined in two opposing directions, we are able to increase the precision of interpolations, suppress oscillations, and improve image sharpness (edge clearness). Subjective and objective evaluations are carried out to verify the basic performance of our method. Under the condition of fixed parameters, experimental results show that our method performs better than the existing methods considered in terms of image quality, both subjectively and objectively. We also varied the value of the reliability parameters to observe the characteristic of our method and how they influence the enlarged image.