Real Time Artifact-Free Image Upscaling

Abstract

Image upscaling (and more generally image interpolation) is the process of resizing a digital image. Enlarging an image is generally common for making smaller imagery fit a bigger screen in full screen mode, for example. In zooming an image, it is not possible to discover any more information in the image than already exists, and image quality inevitably suffers, for that reason several methods have been proposed to obtain better results, involving simple heuristics, edge modeling or statistical learning. The most powerful ones, however, present a high computational complexity and are not suitable for real time applications, while fast methods, even if edge-adaptive, are not able to provide artifacts-free images. So that's why a new method for image upscaling is proposed i.e. Iterative Curvature Based Interpolation (ICBI), it is based on a two-step grid filling and an iterative correction of the interpolated pixels obtained by minimizing an objective function depending on the second order directional derivatives of the image intensity. These are implemented in a variety of computer tools like printers, digital TV, media players, image processing packages, graphics renderers and so on.