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Studies On Bayesian Approaches To Image Restoration And Super Resolution Image Reconstruction

Electronic Theses of Indian Institute of Science

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Field Value
 
Title Studies On Bayesian Approaches To Image Restoration And Super Resolution Image Reconstruction
 
Creator Chandra Mohan, S
 
Subject Image Processing
Image Restoration
Image Reconstruction
Photographic Images
Poisson Blurred Images - Deconvolution
Super Resolution Image Reconstruction
Color Images
Monochrome Images
Bayesain Image Restoration
Bayesian Image Reconstruction
Bayesian Domain
Fuzzy Median Filter
Poisson Images
Applied Optics
 
Description High quality image /video has become an integral part in our day-to-day life ranging from many areas of science, engineering and medical diagnosis. All these imaging applications call for high resolution, properly focused and crisp images. However, in real situations obtaining such a high quality image is expensive, and in some cases it is not practical. In imaging systems such as digital camera, blur and noise degrade the image quality. The recorded images look blurred, noisy and unable to resolve the finer details of the scene, which are clearly notable under zoomed conditions. The post processing techniques based on computational methods extract the hidden information and thereby improve the quality of the captured images.
The study in this thesis focuses on deconvolution and eventually blind de-convolution problem of a single frame captured at low light imaging conditions arising from digital photography/surveillance imaging applications. Our intention is to restore a sharp image from its blurred and noisy observation, when the blur is completely known/unknown and such inverse problems are ill-posed/twice ill-posed. This thesis consists of two major parts. The first part addresses deconvolution/blind deconvolution problem using Bayesian approach with fuzzy logic based gradient potential as a prior functional.
In comparison with analog cameras, artifacts are visible in digital cameras when the images are enlarged and there is a demand to enhance the resolution. The increased resolution can be in spatial, temporal or even in both the dimensions. Super resolution reconstruction methods reconstruct images/video containing spectral information beyond that is available in the captured low resolution images. The second part of the thesis addresses resolution enhancement of observed monochromatic/color images using multiple frames of the same scene. This reconstruction problem is formulated in Bayesian domain with an aspiration of reducing blur, noise, aliasing and increasing the spatial resolution. The image is modeled as Markov random field and a fuzzy logic filter based gradient potential is used to differentiate between edge and noisy pixels. Suitable priors are adaptively applied to obtain artifact free/reduced images.
In this work, all our approaches are experimentally validated using standard test images. The Matlab based programming tools are used for carrying out the validation. The performance of the approaches are qualitatively compared with results of recently proposed methods. Our results turn out to be visually pleasing and quantitatively competitive.
 
Contributor Rajan, K
 
Date 2015-11-24T07:20:13Z
2015-11-24T07:20:13Z
2015-11-24
2012-07
 
Type Thesis
 
Identifier http://etd.iisc.ernet.in/handle/2005/2490
http://etd.ncsi.iisc.ernet.in/abstracts/3215/G25427-Abs.pdf
 
Language en_US
 
Relation G25427