Tree-Based Resolution Synthesis.
Clayton Brian Atkins, Charles A. Bouman, Jan P. Allebach · 1999
In this paper, we present an approach to optimal image scaling called Tree-Based Resolution synthesis (TBRS). TBRS works by first performing a fast local classification of a window around the pixel being interpolated, and then by applying an interpolation filter designed for the selected class. The idea behind TBRS is to use a regression tree as a piecewise linear approximation to the conditional mean estimator of the high-resolution image given the lowresolution image. We generate the parameters for the regression tree by training on sample images. The training is computationally demanding, but it only needs to be performed once. We will demonstrate that the resulting predictor may be used effectively on input images that were not used in the training. 1 Introduction An image is usually only available at one or a few resolutions, so that in order to render it at a higher resolution, some image scaling technique must be applied. This involves some inference on the part of the interpo...