الفهرس 
AbstractOnly 14 pages are availabe for public view
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Abstract
Mobile devices enable new kinds of AR applications since the user is able to move around and is not bound to a stationary computer. The mean of rendering virtual objects realistically in an AR scene is making it hard for an observer to distinguish between virtual and real objects in the rendered image. The visual consistency of virtual and real objects is the goal to be achieved. A high visual consistency can be essential for some applications and it can increase the user’s immersion. Realistic rendering technique of outdoor AR has been an attractive topic since last decades due to the large number of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as shadows, daylight and interaction between virtual and real objects. In this thesis, a system was proposed to improve the creation of the shadow of the virtual object in the enhanced mobile reality systems and to track the changes that occur to the shadow during the movement of the object and to solve the problem of overlapping shadows that may be produced by the movement of the virtual object in the outdoor during the day. This approach involved three main phases, which cover different outdoor augmented reality rendering requirements. The rendering consists of a three phase: shadow detection, shadow protection and shadow generation. The first phase started with the introduction of a coherent formula for the sun position. Once the true shadow contour is known, it is possible to calculate a rating variable per material in shadow that reflects the color intensity in the shadow region. The second phase a protection mask is created to prevent further rendering in the real shadow regions. During this phase the problem of shadow overlapping are solved. Finally, the virtual shadows are generated using VSM real-time shadow method and a pre-defined rating variable that adapts the intensity of the virtual shadows to the real shadow. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor augmented reality rendering thus solving the problem of realistic augmented reality systems.