Computer
Dhuha Abd Almoanf; Shaimaa H. Shaker
Abstract
Computed tomography (CT) is used to diagnose diseases and tumors. A special dye called contrast material is used in CT scans to assist emphasize the parts of the body being examined. Therefore, an enhancement technique to improve CT images' degradation is needed. This paper aims to present a method to ...
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Computed tomography (CT) is used to diagnose diseases and tumors. A special dye called contrast material is used in CT scans to assist emphasize the parts of the body being examined. Therefore, an enhancement technique to improve CT images' degradation is needed. This paper aims to present a method to enhance the quality of Ct-Scan images based on discrete wavelets transform and the Retinex algorithm. The proposed methods are based on the Retinex algorithm parameters or Dark Channel Prior algorithm parameters, according to the output image from preprocessing and discrete wavelets algorithm steps to increase the lightness degree of an image, remove possible noise from the image improve the contrast. The results of experiments of the enhanced image outputted from the Retinex model compared with one outputted from the Dark Channel Prior method. Hence, image quality based on the DCP method is a higher degree of enhanced rate and reasonable rate of noise removal-based enhancement measures, which were SI, MSE, IQI, SNR, and SNR, but was very attentive to the percentage values of IQI and SI. So the DCP with WT was recorded as the highest rate of enhancement.
Nashwan Alsalam Ali; Abdul Monem S Rahma; Shaimaa h. Shaker
Abstract
The widespread of recent multimedia, including various 3D model applications in different domains of areas, may lead to 3D models being stolen and attacked by hackers. Moreover, 3D models must be protected from unauthorized users and when transmitting over the internet. Nowadays the 3D model protection ...
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The widespread of recent multimedia, including various 3D model applications in different domains of areas, may lead to 3D models being stolen and attacked by hackers. Moreover, 3D models must be protected from unauthorized users and when transmitting over the internet. Nowadays the 3D model protection is a very important issue. This paper proposed a scheme that provides high protection for the textured 3D model by implementing multiple levels of security. The first level of security is achieved by encrypting the texture map based on a key generated by a 2D Logistic chaotic map. The second level of security is implemented by modifying the vertices values of the 3D mesh based on keys generated by the 3D Lorenz chaotic map. The proposed scheme was implemented on various 3D textured models varying in the number of vertices and faces. The experimental results show that the proposed scheme has a good encryption and provides high security by completely deforms the whole texture and 3D mesh of the textured 3D model into the two levels. The encryption scheme has a large key space 10135 making the scheme resists violent attacks. The Hausdorff Distance (HD) and histogram metrics are adopted to calculate the matching degree between the original and extracted model. The results show that the original and extracted model are identical through the values of HD, which are approximate to zero, and the histogram visually is similar.
