Real-time 2D/3D display of dted maps and evaluation of interpolation algorithms

Download
2010
Demir, Ali
In Geographic Information System (GIS) applications, aster data constitutes one of the major data types. The displaying of the raster data has an important part in GIS applications. Digital Terrain Elevation Data (DTED) is one of the raster data types, which is used as the main data source in this thesis. The DTED data is displayed on the screen as digital images as a pixel value, which is represented in gray scale, corresponding to an elevation (texel). To draw the images, the texel values are mostly interpolated in order to perform zoom-in and/or zoom-out operations on the concerned area. We implement and compare four types of interpolation methods, nearest neighbor, bilinear interpolation, and two new proposed interpolation methods (1) 4-texel weighted average and (2) 8-texel weighted average. The real-time graphical display, with zoom-in/zoom-out capabilities, has also been implemented by buffering DTED data in memory and using a C++ clas that manages graphical operations (zoom-in, zoom-out, and 2D, 3D isplay) by using Windows GDI+ and OpenGL graphic ibraries resulting in 30-40 framesper-second for one grid of DTED Level 0 data.

Suggestions

Retrospective adaptive prefetching for interactive Web GIS applications
Yesilmurat, Serdar; İşler, Veysi (2012-07-01)
A major task of a Web GIS (Geographic Information Systems) system is to transfer map data to client applications over the Internet, which may be too costly. To improve this inefficient process, various solutions are available. Caching the responses of the requests on the client side is the most commonly implemented solution. However, this method may not be adequate by itself. Besides caching the responses, predicting the next possible requests from a client and updating the cache with responses for those re...
Indexing Fuzzy Spatiotemporal Data for Efficient Querying: A Meteorological Application
Sozer, Aziz; Yazıcı, Adnan; Oğuztüzün, Mehmet Halit S. (2015-10-01)
Spatiotemporal data, in particular fuzzy and complex spatial objects representing geographic entities and relations, is a topic of great importance in geographic information systems and environmental data management systems. For database researchers, modeling and designing a database of fuzzy spatiotemporal data and querying such a database efficiently have been challenging issues due to complex spatial features and uncertainty involved. This paper presents an integrated approach to modeling, indexing, and ...
Derivation of Transcriptional Regulatory Relationships by Partial Least Squares Regression
Tan, Mehmet; Polat, Faruk; Alhajj, Reda (2009-11-04)
As the number of genes in a transcriptional regulatory network is large and the number of samples in biological data types is usually small, there is a need for integrating multiple data types for reverse engineering these networks. In this paper, we propose a method to integrate microarray gene expression, ChIP-chip and transcription factor binding motif data sets in a partial least squares regression model to derive transcription factors (TFs) gene interactions. Both single and synergistic effects of TFs ...
Implementation of x-tree with 3d spatial index and fuzzy secondary index
Keskin, Sinan; Yazıcı, Adnan; Oğuztüzün, Mehmet Halit S.; Department of Computer Engineering (2010)
Multidimensional datasets are getting more extensively used in Geographic Information Systems (GIS) applications in recent years. Due to large volume of these datasets efficient querying becomes a significant problem. For this purpose, before creating index structure with these enormous datasets, choosing an efficient index structure is an urgent necessity. The aim of this thesis is to develop an efficient, flexible and extendible index structure which comprises 3D spatial data in primary index and fuzzy at...
Design and implementation of spatiotemporal databases
Sözer, Aziz; Yazıcı, Adnan; Oğuztüzün, Mehmet Halit S.; Department of Computer Engineering (2010)
Modeling spatiotemporal data, in particular fuzzy and complex spatial objects representing geographic entities and relations, is a topic of great importance in geographic information systems, computer vision, environmental data management systems, etc. Because of complex requirements, it is challenging to design a database for spatiotemporal data and its features and to effectively query them. This thesis presents a new approach for modeling, indexing and querying the spatiotemporal data of fuzzy spatial an...
Citation Formats
A. Demir, “Real-time 2D/3D display of dted maps and evaluation of interpolation algorithms,” M.S. - Master of Science, Middle East Technical University, 2010.