1-2hit |
Hitoshi TAKEOKA Tomozo FURUKAWA Goro MATSUMOTO
A nonlinear modified Laplacian operator for ridgeline extraction in a picture is proposed. The operator shows better performance in enhancing the ridgeline and suppressing noise compared with the conventional Laplacian operator.
A method for designing two-dimensional FIR fan filters has been developed. With the proposed method, any size (i.e., even or odd) fan filter can be designed by extending a 1-D FIR prototype filter. This extension is performed by rotating and linearly interpolating the frequency response of the 1-D FIR prototype, and cascading an attenuator. The 2-D FIR fan filter obtained has specified number of fans and specified pass orientation. This has not been accomplished by conventional methods. The principle of the extension, examples of designing and the application in filtering are presented.