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Abstract The thesis is concerned with the problem of simultaneous enhanced fusion and interpolation of infrared (IR) and visible images. IR imaging techniques can be used to image the temperature distribution of an object. IR images have low contrast between background and targets and small Signal-to-Noise Ratios (SNRs). These characteristics reduce the detectability of targets from IR images. In order to recognize targets correctly from these images, efficient enhancement approaches must be applied, firstly. The aim of image enhancement is improving the visibility of low contrast images, decreasing the noise to obtain an image with as much detail as possible, and to produce reliable methods that represent the visual information, obtained from a number of imaging techniques, in a single fused image with more information. In this thesis, two suggested enhancement approaches for IR images are presented; a visual quality enhancement approach and a resolution enhancement approach. The visual quality approach is based on curvelet transform and homomorphic processing using the additive wavelet transform (AWT), Different image fusion methods are presented. The traditional techniques of fusion such as wavelet based fusion are discussed in the thesis. Then, the idea of curvelet fusion used in satellite and medical applications is adopted to the fusion of IR and visible images with success and gives good fusion results. The steps of the curvelet transform are implemented to both IR and visible images. This transform is based on the segmentation of the whole image into small overlapping tiles and then, the ridgelet transform is applied to each tile, then the fusion process is performed. II The resolution enhancement approach is based on image interpolation, where the enhanced fusion results are then interpolated with inverse techniques to give high resolution images. Three inverse interpolation techniques are used for the interpolation of enhanced curvelet fusion results. The results obtained reveal the superiority of the inverse interpolation techniques to the polynomial based techniques to obtain high resolution fusion results. The thesis comprises five chapters. Chapter 1 presents an introduction for the low contrast images. It covers the applications of IR imaging. In addition, this chapter discuses the two suggested enhancement approaches, image fusion, and interpolation. Chapter 2 covers some characteristics of IR images. It gives the different spectrum regions that can be classified as IR ranges. It gives a good understanding of IR images. This chapter gives also a description of an IR imaging system and its applications. Chapter 3 gives a literature review of image fusion concepts. Some different techniques of image fusion are revised. The chapter concentrates on discrete wavelet transform (DWT), and dual tree complex wavelet transform (DT-ı WT) based image fusion, and the mathematical representation of the curvelet transform. An enhanced fusion technique for IR and visible images, which is based on the curvelet transform and homomorphic processing using the AWT, is presented in this chapter. Moreover, the enhanced fused image based on the curvelet transform is compared to wavelet transforms (WT) based image fusion results. Finally, the image quality metrics, which will be used throughout the thesis for the assessment of the obtained results, are presented.In chapter4, image interpolation for the enhanced fusion results is studied. Some image interpolation algorithms are introduced taking into consideration the low resolution (LR) image degradation model. A comparison study between these algorithms and the traditional cubic spline interpolation algorithm is presented. The concluding remarks and the future work are presented in chapter 5. |