Please use this identifier to cite or link to this item:

Underwater machine vision : recovering orientation and motion of Lambertian planar surfaces in light attenuating media

File Description Size Format  
uhm_phd_9118071_r.pdf Version for non-UH users. Copying/Printing is not permitted 3.53 MB Adobe PDF View/Open
uhm_phd_9118071_uh.pdf Version for UH users 3.49 MB Adobe PDF View/Open

Item Summary

Title:Underwater machine vision : recovering orientation and motion of Lambertian planar surfaces in light attenuating media
Authors:Yu, Zhihe
Keywords:Underwater television
Computer vision
Optical oceanography
Date Issued:1990
Abstract:Although much progress has been made for land-based systems, the developed techniques cannot be directly applied in environments where attenuation of light intensity is significant, and artificial lighting is the only source of illumination, as in deep ocean environments. To achieve this, various illumination effects including those caused by an artificial light source with limited power and light intensity attenuation due to absorption and scattering in the medium should be taken into account. In this dissertation, equations for scene radiance and image irradiance are developed which model the attenuation phenomenon in an absorbing and scattering medium such as sea water. Based on these models, the reflectance map for a Lambertian surface illuminated by a point light source is derived. The dissertation then shows how the orientation of planar patches with Lambertian reflectance properties can be recovered from their image shading. Closed-form solutions are given for cases when either parallel or perspective projection is assumed. In either case, more robust solutions can be obtained when other information such as distance to the surface is known. This dissertation also investigates effects due to motion of the camera and light source relative to the scene. Based on a general brightness change equation, pure translational motion and pure rotational motion are discussed. A least square formula is derived to recover general motion of an object provided it has three or more planar patches which can be identified. Computer simulation results are presented to show the sensitivity of these solutions to noise in the data.
Description:Thesis (Ph. D.)--University of Hawaii at Manoa, 1990.
Includes bibliographical references (leaves 124-130)
x, 130 leaves, bound ill. 29 cm
Rights:All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Appears in Collections: Ph.D. - Electrical Engineering

Please email if you need this content in ADA-compliant format.

Items in ScholarSpace are protected by copyright, with all rights reserved, unless otherwise indicated.