Second Interim Technical Report for Advanced Research in Range Image Interpretation for Automated Mail Handling

This is the report on range image interpretation of singulated irregular parcels. The overall approach to this problem was to find the most general and generic method that will interpret the data yet is computationally economical. We have observed that the large majority of objects that are classified as Irregular Parcels are convex or can be modeled as such plus some deformation. Hence the primitive model that we have chosen, is the superquadric plus deformations such as tapering and bending along the major axis. The superquadric model is an analytic representation of volume for which cross-sections are a class of curves varying between rectangular to elliptical (of course, circular and square shapes are included). As a side product of this representation we obtain naturally the position, orientation and the scale of the object. The principle of recognition is a fitting procedure which changes the parameters so as to minimize the difference between the data and the volume of the model. We believe that this approach is more general than any previously model based approach including CAD/CAM systems. In comparison to the Generalized Cylinder model proposed by Binford [3] and continued with his students [13], our model has the advantages that: a) It does not require any preprocessing, that is the fitting is performed on raw 3-D data points. b) The interpretation is performed in coarse to fine fashion, or from global to local. Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MSCIS-88-43. Author(s) Ruzena K. Bajcsy, Kwangyoen Wohn, Franc Solina, Alok Gupta, Pramath Sinha, and Constantine J. Tsikos This technical report is available at ScholarlyCommons: http://repository.upenn.edu/cis_reports/696 SECOND INTERIM TECHNICAL REPORT FOR ADVANCED RESEARCH IN RANGE IMAGE INTERPRETATION FOR AUTOMATED MAIL HANDLING Ruzena K. BaJcsy, Kwangyoen Wohn, Franc Solina, Aiok Gupta, Pramath Slnha and Constantine J. Tsikos MSICIS-88-43 GRASP LAB 146 Department of Computer and Information Sclence School of Engineering and Applied Sclence University of Pennsylvania Phlladeiphia, PA 191 04 (Revised February 1989) Acknowledgements: This research was supported in part by U.S. Postal Service grant 104230-87-M-0195, NSF-CER grant MCS-8219196, U.S. Army grants DAA29-84-K-0061, DAA29-84-9-0027, LORD Corporation and IMB Corporation grants. SECOND INTERIM TECHNICAL REPORT FOR ADVANCED RESEARCH IN RANGE IMAGE INTERPRETATION FOR AUTOMATED MAIL HANDLING BOA CONTRACT: 104230-87-H-0001/M-0195 Prepaxed for: Office of Advanced Technology Technology Resource Department United States Postal Service Washington, DC 20260-7140 Prepared by: University of Pennsylvania Department of Computer and Information Science 200 South 33rd. Street Philadelphia, PA 19104-6389