Interpenetrating Waves and Multiple Generation Shocks via the CEDT

This volume contains papers presented at the Third International Workshop on Visual Form. It covers the most important topics of current interest in the field, presenting an updated collection of results achieved by leading academic and industrial research groups from several countries. The book contains invited lectures and research papers dealing with theoretical and applicative aspects of shape perception, representation, decomposition, description and recognition, as well as related topics

Conservation-Minded Evolution of Shape

©1990 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.DOI: 10.1109/ISIC.1990.128457Presented at the 5th IEEE International Symposium on Intelligent Control, 5-7 September 1990, Philadelphia, PAMost natural and artificial systems rely heavily on vision to recognize, manipulate, and navigate within a world of objects. Although shape is a key element in this process, its representation and analysis have proved to be a difficult, multifaceted problem. A framework, based on conservation laws, which gives rise to computational elements for shape parts, protrusions, and bends, is proposed. The computation takes place in the context of a reaction-diffusion space and is highly robust. This scheme is ideally suited to object recognition and has applications in areas ranging from robotics to the psychology and the physiology of form

Symmetry Maps of Free-Form Curve Segments Via Wave Propagation

This paper presents an approach for computing the symmetries (skeletons) of an edge map consisting of a collection of curve segments. This approach is a combination of analytic computations in the style of computational geometry and discrete propagations on a grid in the style of the numerical solutions of PDE's. Specifically, waves from each of the initial curve segments are initialized and propagated as a discrete wavefront along discrete directions. In addition, to avoid error built up due to the discrete nature of propagation, shockwaves are detected and explicitly propagated along a secondary dynamic grid. The propagation of shockwaves, integrated with the propagation of the wavefront along discrete directions, leads to an exact simulation of propagation by the Eikonal equation. The resulting symmetries are simply the collection of shockwaves formed in this process which can be manipulated locally, exactly, and efficiently under local changes in an edge map (gap completion, remova..

From the Infinitely Large to the Infinitely Small

We conclude the book by covering a wide spectrum of applications of medial symmetries of shape from the infinitely large toward the infinitely small. Our journey starts with a dynamic model of the formation and evolution of galaxies. We move on to the description of geographical information at the scale of regions of planet Earth. Next is the representation of cities, buildings, and archaeological artifacts, followed by the perception of gardens and the generation of virtual plants. Having reached the scale of human activities, we consider the perception and generation of artistic creations, the study of motion and the generation of animated virtual objects, and the representation of geometrically complex systems in machining, metal forging and object design. We then move inside the human body itself with applications in medical imaging and biology, followed by the representation of molecular structures. Our final stop is to consider the abstract scale of the perception of visual information