الفهرس 
Chapter 1:IntroductionOnly 14 pages are availabe for public view
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Abstract
ABSTRACT
This thesis deals with the issue of quality enhancement of digital images. Both
contrast and resolution enhancements are considered simultaneously. Contrast
enhancement is performed with histogram equalization (HE) and Contrast Limit Adaptive
Histogram Equalization (CLAHE). The CLAHE proved to have the best performance due
to its adaptive nature. The resolution enhancement is performed with interpolation
techniques. Both polynomial and inverse interpolation techniques are considered and
compared. The main advantage of the inverse interpolation is that the low resolution
degradation model is inverted in the interpolation process.
Four hybrid enhancement models are presented in this thesis based on the selection
of the CLAHE and interpolation schemes. Simulation results reveal that the inverse
interpolation in conjunction with the regularized interpolation achieves the best
performance. This is attributed to the constraints on the inverse solution that preserve
smoothness of flat areas and sharpness of edges and also to the adaptive nature of the
CLAHE.There are no reference images to measure the quality with in the assessment
process. Therefore, there is a need to use no-reference quality metrics in the assessment.
We will adopt some metrics for this purpose including average intensity, contrast, spatial,
and spectral entropies