DIRECTIONAL ADAPTIVE NOISE REDUCTION

摘要

An image is processed taking into account the direction of a predominant structure of the image. Said predominant direction is derived from image information in the image. In particular, according to the invention the covariance matrix having matrix elements depending on products of differences between pixel-values in separate directions is calculated. The eigenvectors of the covariance matrix correspond with the predominant direction of the image structure and the eigenvalues of the covariance matrix represent the strength of the structure in the image. The covariance matrix is computed locally, i.e. for separate regions in the images so as to take variations of the direction of predominant structures into account.