Practical Elliptical Texture Filtering on the GPU

Abstract. The seismic section image contains a wealth of texture detail information, which is important for the interpretation of the formation profile information. In order to enhance the texture detail of the image while keeping the structural information of the image intact, a multi-scale enhancement method based on wavelet transform is proposed. Firstly, the image is wavelet decomposed to obtain a low-frequency structural component and a series of high-frequency texture detail components. Secondly, bilateral texture filtering is performed on the low-frequency structural components to filter out high-frequency noise while maintaining the edges of the image; adaptive enhancement is performed on the high-frequency detail components to filter out low-frequency noise while enhancing detail. Finally, the processed high- and low-frequency components reconstructed by wavelets can obtain a seismic section image with enhanced detail. The method of this paper enhances the texture detail information in the image while preserving the edge of the image.

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Reliable GPU-Based Methods and Algorithms of Implementation Dynamic Relief Shadows in Virtual Environment Systems

10.20948/graphicon-2021-3027-83-94 ◽

2021 ◽

Author(s):

Petr Timokhin ◽

Mikhail Mikhaylyuk

Keyword(s):

Data Structure ◽

Real Time ◽

Virtual Environment ◽

Scientific Visualization ◽

Ray Casting ◽

Software Complex ◽

Texture Filtering ◽

Educational Applications

The paper considers the task of real-time rendering of dynamic relief shadows based on ray casting using origin relief data - detailed height map. The solution proposed is based on looking for shadow rays - sun rays, whose tracks on height map are passed through heights occluding the light. GPU-based methods and algorithms for extracting such rays using an accelerating data structure - a mipmap of maximum and minimum relief heights are developed. This structure provides an effective acceleration of shadow rays extraction by skipping long sections of sun ray tracks that are not involved in relief shadowing. In algorithms developed precise traversing such a data structure is implemented, as well as texture filtering is taking into account, which allows the formation of "torn" shadow edges to be prevented. The solution created was implemented in software complex and a number of comparative shadow visualization tests was conducted. The results of the research can be used in virtual environment systems, video simulators, scientific visualization, educational applications, etc.

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