Image analyser and adaptive image scaling circuit and methods

Abstract

An image analyser analyses regions of an image. An image scaler may then scale the image adaptively, in dependence on the nature of region of the image being scaled. In one embodiment, adjacent pixels are analysed to determine their frequency content. This frequency analysis provides an indication of whether the pixels likely contain hard edges, discontinuities or variations typical of computer generated graphics. As a result of the analysis, the type of scaling suited for scaling the image portion containing the pixels may be assessed. Adjacent pixels having high frequency components may be scaled by a scaling circuit that introduces limited ringing. Adjacent pixels having lower frequency components may be scaled using a higher-order multi-tap scaler. Resulting scaled pixels may be formed as a blended combination of the two different scaling techniques.