Design of an Online GIS Viewer by Wavelet Technology
Jingsong Wu, Kevin S. Amaratunga, Tuck Meng Lui · 2000
Along with the high-speed development of the Internet, users have begun to expect highly interactive online GIS. Wavelet technology provides an efficient approach to achieve this. Wavelet analysis is a new mathematical tool, which allows a complex system to be analyzed into different scales. Using this technology, one can decompose an image into a hierarchy of sub-images. Based on different requirements, these sub-images can be processed in various ways and then used to reconstruct the original image or an approximation of the original image. This paper describes how to use wavelet technology to design an interactive online GIS viewer, which can be used to query high-resolution images in different scales. This technology is potentially useful for large online GIS because each scale of the decomposed image can be transferred separately over the Internet or an Intranet. It provides an approach to solve the problem of transferring a huge amount of data for large images over a relatively low speed network. It is especially useful for image manipulation, such as zooming and panning. To demonstrate the capability of this technology, a prototype online GIS viewer is implemented using a wavelet scheme known as lifting.