Local Rotational Symmetries

Item

Title: en_US Local Rotational Symmetries
Creator: en_US Fleck, Margaret Morrison
Date: 2004-10-20T20:03:57Z
Date Available: 2004-10-20T20:03:57Z
Date Issued: en_US 1985-08-01
Identifier: en_US AITR-852
uri: http://hdl.handle.net/1721.1/6877
Abstract: en_US This thesis describes a new representation for two-dimensional round regions called Local Rotational Symmetries. Local Rotational Symmetries are intended as a companion to Brady's Smoothed Local Symmetry Representation for elongated shapes. An algorithm for computing Local Rotational Symmetry representations at multiple scales of resolution has been implemented and results of this implementation are presented. These results suggest that Local Rotational Symmetries provide a more robustly computable and perceptually accurate description of round regions than previous proposed representations. In the course of developing this representation, it has been necessary to modify the way both Smoothed Local Symmetries and Local Rotational Symmetries are computed. First, grey-scale image smoothing proves to be better than boundary smoothing for creating representations at multiple scales of resolution, because it is more robust and it allows qualitative changes in representations between scales. Secondly, it is proposed that shape representations at different scales of resolution be explicitly related, so that information can be passed between scales and computation at each scale can be kept local. Such a model for multi-scale computation is desirable both to allow efficient computation and to accurately model human perceptions.
Extent: en_US 156 p.; 12727669 bytes; 8847371 bytes
Format: application/postscript; application/pdf
Language: en_US
Relation: en_US AITR-852

Item sets: AI Technical Reports (1964 - 2004)