Modified New Edge-Directed Interpolation Using Window Extension

Abstract

In this paper, we proposed modified NEDI (New Edge-Directed Interpolation) method using recursive window extension and clipping technique. The conventional NEDI interpolates HR pixels based on the geometric duality between HR (high resolution) and LR (low resolution) pixels. When the reference pixels in the window have different structures locally, the calculation of interpolation coefficients can be greatly affected. This is because when using geometric duality, pixels are used in the limited window. Also, if the structures of the reference pixels in the window are different from each other, there is a problem that the geometric duality between the HR and LR pixels is reduced and distortion occurs. In this paper, we used recursive window extension method for improving the structural similarity of the pixels in the window and clipping technique for increasing the geometric duality. Experimental results show that the results of various algorithms are compared and subjective and objective image quality is improved compared to the conventional NEDI.