Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images

This research focuses on a type of information provided by the pixels in intensity images. The types of images that are the focus of this research are scanning electron microscopy (SEM) and magnetic resonance imaging (MRI) images. These two types of images were chosen for the amount of details that...

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Main Author: Chan, Wai Ti
Format: Thesis
Published: 2019
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spelling my-mmu-ep.77672020-09-22T17:53:39Z Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images 2019-10 Chan, Wai Ti TA1501-1820 Applied optics. Photonics This research focuses on a type of information provided by the pixels in intensity images. The types of images that are the focus of this research are scanning electron microscopy (SEM) and magnetic resonance imaging (MRI) images. These two types of images were chosen for the amount of details that they can present using intensity values. In turn, the details that they provide lead to the use of the secondorder derivatives of the values of pixels. The second-order derivatives provide further information about the images, specifically their levels of noise and contrast. The second-order derivatives are obtained from applying a Laplacian operator on the pixels in the image. The second-order derivatives of the pixels can be collected into histograms, which are henceforth referred to as “second-order histograms”. These histograms have shape profiles with certain characteristics that are common to all images with adequate contrast and low levels of noise, e.g. profiles that approximately resemble Laplace distribution profiles. The main theory in this research is that any deviation from these presence is an indicator of the presence of factors that affect the quality of an image. One of the characteristics of the Laplace distribution profile is the convergence of two concave and non-contiguous curves into a sharp peak. The peak contains data on image details that have uniform intensity, such as regions of the same material in SEM images. Therefore, the absence of the peak in the second-order histogram of an image indicates the presence of factors that affect those details, such as noise. This is the idea behind a method to reduce noise through the restoration of the Laplace distribution profile by changing the pixel values of an image. 2019-10 Thesis http://shdl.mmu.edu.my/7767/ http://library.mmu.edu.my/library2/diglib/mmuetd/ phd doctoral Multimedia University Faculty of Engineering & Technology
institution Multimedia University
collection MMU Institutional Repository
topic TA1501-1820 Applied optics
Photonics
spellingShingle TA1501-1820 Applied optics
Photonics
Chan, Wai Ti
Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images
description This research focuses on a type of information provided by the pixels in intensity images. The types of images that are the focus of this research are scanning electron microscopy (SEM) and magnetic resonance imaging (MRI) images. These two types of images were chosen for the amount of details that they can present using intensity values. In turn, the details that they provide lead to the use of the secondorder derivatives of the values of pixels. The second-order derivatives provide further information about the images, specifically their levels of noise and contrast. The second-order derivatives are obtained from applying a Laplacian operator on the pixels in the image. The second-order derivatives of the pixels can be collected into histograms, which are henceforth referred to as “second-order histograms”. These histograms have shape profiles with certain characteristics that are common to all images with adequate contrast and low levels of noise, e.g. profiles that approximately resemble Laplace distribution profiles. The main theory in this research is that any deviation from these presence is an indicator of the presence of factors that affect the quality of an image. One of the characteristics of the Laplace distribution profile is the convergence of two concave and non-contiguous curves into a sharp peak. The peak contains data on image details that have uniform intensity, such as regions of the same material in SEM images. Therefore, the absence of the peak in the second-order histogram of an image indicates the presence of factors that affect those details, such as noise. This is the idea behind a method to reduce noise through the restoration of the Laplace distribution profile by changing the pixel values of an image.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Chan, Wai Ti
author_facet Chan, Wai Ti
author_sort Chan, Wai Ti
title Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images
title_short Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images
title_full Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images
title_fullStr Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images
title_full_unstemmed Application Of Second-Order Histograms In Noise Reduction And Contrast Measurement Of Intensity Images
title_sort application of second-order histograms in noise reduction and contrast measurement of intensity images
granting_institution Multimedia University
granting_department Faculty of Engineering & Technology
publishDate 2019
_version_ 1747829677717716992