الفهرس 
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Abstract
Digital cameras provided a great service for users of all ages because it makes it easier to take images, although the user still needs to improve some images tinged lack of clarity when capturing an image due to the lack of proper lighting as in cloudy weather, bright or dark sites light, take an image from a distance, resulting in blurred image details.
Proposed in this thesis a new method for contrast enhancement in gray images using two applications of mathematical digital transforms. The first transform is based on Fast Discrete Curvelet Transform via Unequally Spaced Fast Fourier Transform (FDCT-USFFT), while the second transform is based on Fast Discrete Curvelet Transform via wrapping (FDCT-Wrap) of specially selected Fourier samples. These types of transforms return a table of curvelet coefficients indexed by the scale parameter, an orientation, and a spatial location.
The FDCT-USFFT and FDCT-Wrap coefficients can be modified to enhance the contrast in an image.
Results show that the proposed techniques gave better results, in comparison with the histogram equalization and wavelet transform based contrast enhancement method. Moreover, we compare between the two proposed techniques and results show that FDCT-Wrap is better than FDCT-USFFT based contrast enhancement in gray images.