Method and apparatus for contour tracking of an image through a class of non linear filters

摘要

A method for automatically detecting and tracking the contour of an image that uses a class of filters, obtained from the first order absolute central moment. The method provides the steps of filtering a starting image through the absolute central moment e(n,m) of the intensity of a pixel of said image, being n and m the coordinates of each pixel, where the absolute central moment is obtained with the following steps: determining for each n,m the local mean calculated in a neighborhood about a pixel of coordinates n,m of the starting image, thus obtaining a first filtered image; determining for each n,m the sum of the absolute differences between the intensity of a pixel of coordinates n,m of the first filtered image and the intensity of all the pixels contained in a neighborhood about a pixel of coordinates n,m of either said starting image or a second filtered image obtained from said starting image. The images to treat can be of various type and belonging to many different fields, among which robotics, control of industrial processes, medicine, multimedia applications, safety systems, and can be color or grey levels images. The bidimensional images can give place to volumetric images or panoramic images if acquired as spatial sequences of slices.