الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
Digital Elevation Models (DEMs) may be generated either using contours or using remote sensing techniques such as RADAR interferometric techniques and SPOT stereo-pairs interferometer. A density sliced DEM that is converted to topographic map lacks the topographic features. In order to regenerate the view instantly with different parameters,a quick and optimized method is required. Using a 2D-mapping for 3D visualization that produces time optimized shading improves topographic information. An optimized framework SHADGPU to calculate shadows from DEM is proposed. A first optimization minimizes the calculations of normal vectors at each image pixel in addition made it independent of each other. Putting into consideration that the generated DEM could be stored as an image with real or floating point values therefore preserves the accuracy of parameters. This process leads itself naturally to the parallel model, thus a second optimization using GPGPU is performed. Numerical outcomes show excellent results, the framework yields faster results than without using the framework.
In chapter 1 section 1 introduces digital images,how analog images are converted to digital,it discusses the acquisition techniques for digital images and finally image processing classes and components.
Section 2 starts with describing some basic relationships between pixels and then followed by introducing some general image processing techniques including arithmetic based operations, histogram based operations and finally summary on filtering operations is introduced.
Chapter 2 is focused on a specific type of digital images which are satellite images and remotely sensed data. Section 1 introduces the remote sensing process which starts with identifying the problem to be solved via remotely collecting data followed by data analysis and ended up with information output, at the end of this Section remote Sensing applications review is provided.
Section 2 describes remote sensing data management including digital image formats and data exchange standards, section 2.3 is focused on satellite image processing techniques. Some techniques are common general image processing techniques, which was described at chapter 1. Others are dedicated to satellite images such as Radiometric Correction process, Geometric Correction process and Image resampling Methods in addition to enhancement techniques and information extraction techniques.