IMPLEMENTATION OF A 2-D FIR DIGITAL FILTER OF PARABOLIC TYPE FOR BIOMEDICAL APPLICATIONS.

A special 2-D FIR digital filter is presented to process biomedical images, in particular performing enhancement or edge extraction with a controlled action (i. e. to maintain a given amount of information of the low frequency region). The designed digital filter is of 'parabolic' type; it has a circular symmetry and its frequency response is obtained, as a rotation solid, by a generation curve constituted by the interconnection of two parabolas having opposite concavity. Some experimental results are reported, performed on special gray level mask to evaluate the effect on space and contrast resolutions, and on TAC images both including soft tissues (such as brain and lung), medium consistency tissues (cartilage), and hard tissues (bone), to verify the efficiency on different tissue types.