GIs Terrain Data Compression Using Lifting Scheme- A New Dimension

• Autores: B. Pradhan, K. Sandeep, Shattri Mansor, Ramli Abdul Rahman, Abdul Rashid B. Mohamed Sharif
• Localización: International journal of the computer, the internet and management, ISSN 0858-7027, Vol. 15, Nº. 2 (MAY -AGO), 2007, págs. 9-19
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The lifting scheme has been found to be a flexible method for constructing scalar wavelets with desirable properties. In this paper, it is extended to the GIS data compression. A newly developed data compression approach to approximate the land surface with a series of non-overlapping triangles has been presented. Generally a Triangulated Irregular Networks (TIN) is the most common form of digital surface model that consists of elevation values with x, y coordinates that make up triangles. But over the years the TIN data representation has become a case in point for many researchers due to its large data size. Compression of TIN is needed for efficient management of large data and good surface visualization. This approach covers following steps: First, by using a Delaunay triangulation, an efficient algorithm is developed to generate TIN, which forms the terrain from an arbitrary set of data. A new interpolation wavelet filter for TIN has been applied in two steps, namely splitting and elevation. In the splitting step, a triangle has been divided into several sub-triangles and the elevation step has been used to ‘modify’ the point values (point coordinates for geometry) after the splitting. Then, this data set is compressed at the desired locations by using second generation wavelets. The quality of geographical surface representation after using proposed technique is compared with the original terrain. The results show that this method can be used for significant reduction of data set.