Fuzzy logic filter for reducing noise and sharpening edges of digital image signals

摘要

A filter achieving noise reduction and digital signal image edge enhancement includes two noise reduction circuits designed to enhance an image edge. The noise reduction circuits comprise both comparison units, which receive separate digital signals of an image and an inferential circuit connected to said comparison elements. Each inferential circuit uses a fuzzy logic unit designed to define activation levels based on signals generated by the comparison elements. The filter also includes a noise detection circuit and an image edge detection circuit both connected to the noise reduction circuit and designed to perform operations in accordance with fuzzy logic rules on the basis of the activation levels defined in the inferential circuits. The filter also includes a noise reduction circuit connected to the noise detection circuit and is designed to filter the digital image signals on the basis of the operations performed by the noise detection circuit. The filter additionally includes an image edge enhancement circuit connected to the noise reduction circuit and to the image edge detection circuit and is designed to perform on filtered digital image signals image edge enhancement on the basis of the operations performed by the image edge detection circuit.