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Master's Dissertation
DOI
10.11606/D.18.2007.tde-04092007-162846
Document
Author
Full name
Robson Barcellos
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 2007
Supervisor
Committee
Gonçalves Neto, Luiz (President)
Cesar Junior, Roberto Marcondes
Schiabel, Liliane Ventura
Title in Portuguese
Detecção de riscos em lentes esféricas, por luz refletida, através de descritores de Fourier
Keywords in Portuguese
Descritores de Fourier
Iluminação
Lentes orgânicas
Riscos
Ultravioleta
Vetor de características
Abstract in Portuguese
Este trabalho apresenta uma metodologia para inspeção de lentes oftalmológicas orgânicas esféricas durante seu processo de polimento. A metodologia consiste na obtenção de uma imagem em uma câmera de vídeo CCD, usando-se luz ultravioleta, da lente a ser inspecionada, e posterior processamento desta imagem para discriminar a presença de riscos de outros artefatos que poderão aparecer na imagem capturada. Para a detecção da presença de riscos foram utilizados os descritores de Fourier. Atenção especial foi dada à iluminação da lente, que é fator determinante na obtenção de uma boa qualidade de imagem. Os resultados mostram a eficiência do método e permitem sua utilização durante o processo de fabricação de lentes.
Title in English
Detect of scratches in spherical lenses, for light reflected under Fourier descriptors
Keywords in English
Feature vector
Fourier descriptors
Illumination
Organic lenses
Scratches
Ultraviolet
Abstract in English
This work presents a methodology for inspection of spherical organic ophthalmic lenses during the polishing process. The methodology encompasses the capture of an ultraviolet image of the lens under inspection by a CCD video camera and associated processing of the image to discriminate between scratches on the lens and artifacts that can appear on the image. Fourier descriptors were used to detect the existence of scratches. Special attention was given to illumination which is a determining factor in grabbing an image with good quality. The results show that the method is efficient and that it can be used in the lens manufacturing process.
 
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Robson.pdf (18.05 Mbytes)
Publishing Date
2007-09-12
 
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