Multiscale shape analysis based on the Hough transform statistics

Author(s)

Lucas Alexandre Ramos

• Document type: Master's Dissertation
• Press: Bauru. 2016-09-14.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru
• Defense date: 2016-08-12
• Advisor: Aparecido Nilceu Marana

Abstract

Currently, given the widespread of computers through society, the task of recognizing visual patterns is being more and more automated, in particular to treat the large and growing amount of digital images available. Applications in many areas, such as biometrics, content-based image retrieval, and medical diagnostic, make use of image processing, as well as techniques for the extraction and analysis of their characteristics, in order to identify persons, objects, gestures, texts, etc. The basic features that are used for image analysis are: color, texture and shape. Recently, it was proposed a new shape descriptor called HTS (Hough Transform Statistics), which is based on the Hough space to represent and recognize objects in images by their shapes. The results obtained by HTS on public image databases have shown that this new shape descriptor, besides showing high accuracy levels, better than many traditional shape descriptors proposed in the literature, is fast, since it has an algorithm of linear complexity. In this dissertation we explored the possibilities of a multiscale and scale-space representation of this new shape descriptor. Scale is a key parameter in Computer Vision and the theory of scale-space refers to the space formed when observing, simultaneously, special aspects of an image at several scales, being the scale the third dimension. The multiscale HTS methods were evaluated on the same databases and their performances were compared with the main shape descriptors found in the literature and with the monoscale HTS. Experimental results showed that these new descriptors are faster and can also be more accurate in some cases. (AU)

• FAPESP's process: 14/10611-0 - Shape analysis with multiscale HTS
• Grantee: Lucas Alexandre Ramos
• Support Opportunities: Scholarships in Brazil - Master