Detailed description follows.
This tutorial covers the basic ideas of invariant theory in a geometric, algebraic and differential framework. We discuss the action of a group on a set through such familiar examples as geometric figures, polynomials and differential curves and surfaces. He has published extensively in these three areas. An algebraic system of operators, such as those of mathematical morphology, is useful for computer vision because compositions of its operators can be formed which, when acting on complex shapes, are able to extract their meaningful parts from their extraneous parts. Such a system of operators and their compositions permit the underlying shapes and their features to be identified from their distorted noisy forms.