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Abstract The impetus for development stems from a steady flow of new, applications of digital image processing are continuous to grow e.g. in· telecommunications, commercial, industry, TV broadcasting, medical imaging,: ’ remote sensing, and scientific research. Thus, with increasing availability of reasonably inexpensive hardware and some very important applications on the horizon, one can expect digital image processing to play an important role in the future. Most media use pictures as optical information carriers. The tremendous volume of these information and the need for its processing paved the way to image processing by digital computers. Soon, a new branch of science called digital image processing emerged. Image processing activity has been devoted to image enhancement and image restoration. Image enhancement allows the observer to see details in images that may not be immediately observable in the original image. This may be the case, for example, when the dynamic range of data and that of the display are not commensurate, when the image has a high level of noise or when contrast is insufficient. By image restoration, we mean the removal or the reduction of degradations that were incurred while the digital image was being obtained i.e. is to bring the image toward what it would have been if it had been recorded without degradations. The old pictures play a great and important role in our coetaneous life. These pictures may be unique pictures for famous persons such as Mohammad Abduh (1849-1905), Mustafa Kamil (1874-1908), and Ismail Pasha (1830- 1895), and important places or for the ordinary people that are difficult or impossible to be taken again. Unfortunately, old pictures are often deteriorated due to aging, improper handling, and changes of chemical used in producing the image. These undesirable phenomena affect the measurement process in . imaging and data acquisition system i.e. the process of transforming these • pictures into digital and recording them on digital recording which means in computers, usmg the scanner, may add some degradations. The different degradations such as noise, geometrical degradation, illumination, color imperfection, and blur, all may produce artifacts in general in the image. One of the foremost considerations is studying the degradation characteristics of the old pictures to avoid these pitfalls in the pursuit of the best possible enhanced and restored images. Objective and Main Contributions of the Thesis In this thesis, the result of an on going study of applying image processing methods in the enhancement and restoration of old pictures will be discussed. The process is not a straight forward but may face many interrupted difficulties. Whatever the difficulties are in the image itself or the method and format used in transferring the image into the computer. The process of image recording produces a noise and the format used to record the image also affect the final results. The type and model of noise in these old pictures are unknown. So, this thesis studies the noise characteristics. The most important result obtained proposes a signal dependent noise model for the noise in the old pictures. The importance of this result is identifying a noise filtering proper method. we applied and compared. the results of some traditional and modified image filtering methods, such as lowpass averaging, median filtering, and adaptive filtering, then, proposed an image enhancement and image restoration • techniques to be applied with the old images. The main contributions can be summarized asfollows:- 1- By using the definitions of the variance and the range we can determine the quantity of the noise reduction , (discussed in chapter three) . 2- Proposed a new image quality measure needs no information about the original image. This measure is useful in different applications such as the fields of old images, radar images, and medical images, (discussed in chapter three) . 3- Studied the characteristics of the old images and categorized their degradations, (discussed in chapter four). 4- Studied the properties of noise m old Images and its classification, (discussed in chapter four). 5- Performed and applied old images to some image processing techniques and comparing the effects of traditional filters in old images, (discussed in chapter jive) . 6- Since there 1s no general enhancement theory moreover the enhancement techniques are interactive and requires a combinations between different methods, we proposed combination methods and applied these methods on old images, (discussed in chapter jive). 7- Proposed some methods to process old images, (discussed in chapter jive). Organization of the Thesis: The thesis includes six chapters. Each chapter deals with a specific topic ’ as follows: In the first chapter, we introduced the important definitions for image . ! processmg. In the second chapter, we introduced the meanmg of convolution ! operation and it’s prosperities, then reviewing some image filtering techniques such as linear filters, non linear filters and applying these filters on some traditional images. In the third chapter, we proposed some measures of noise reduction and image quality without any availability of the reference image which is very important in old images processing. In the fourth chapter, literature survey of nmse types are clearly emphasized, then classified the old images degradations and studied its noise characteristics . In the fifth chapter, we introduced a comparison between the image traditional filters (lowpass-average-median- ...), suggested some combinations between these filters which are suitable for old images. We proposed an image· enhancement and restoration techniques for old images. Finally, m chapter stx, we summarized the results and introduced headlines for suggestion of the future work. |