Method, system and software for improving signal quality using pyramidal decomposition

摘要

A method, system, and software are disclosed for improving the quality of a signal. A base signal is recursively decomposed for a desired number of pyramid levels. The decomposed signal from the lowest level is modified to generate a preprocessed signal. The preprocessed signal from the lowest level is used to improve signal components or characteristics of the decomposed signal of the next higher level of the pyramidal decomposition, resulting in a modified signal at the next higher level. In one embodiment, the preprocessed signal includes filter mask that is used to guide a filtering process on the decomposed signal of the next higher level. In another embodiment, the preprocessed signal includes a up-predicted signal that is combined with the decomposed signal of the next higher level. The preprocessed signal from a lower level is used to generate a modified signal at a higher level. The generation of a preprocessed signal and a modified signal is recursively repeated for each level until the highest level of the pyramidal decomposition is reached, resulting in an improved base signal. The present invention finds particular application in photography and digital film processing, whereby the illustrated method may be used to reduce image noise, thereby improving image quality.