Fast directional image interpolation with difference projection

This paper presents a new directional image interpolator, aiming to increase image resolution with high perceptual quality and low computational complexity. In our method, missing pixels in a magnified image are generated through linear interpolation on certain fixed supports to facilitate fast implementation, while local directional features are imposed on the adaptive interpolation weights which are determined by the gradients diffused from the low resolution image. Afterwards, a novel difference projection strategy is proposed to enforce the continuity of the magnified image by reusing the directional interpolator. Experimental results show that our method outperforms conventional bicubic and some existing adaptive interpolators, in terms of both the perceptual and quantitative quality.