The Web based Geographic Information Systems (GIS) are applied widely, and most of them are facing the challenge of
performance deterioration when have large capacity data and the demand of interactive application within web page. In
this paper, a system named Foshan city Police GIS (PGIS) has been constructed based on ArcServer (published by ESRI
company) to satisfy the demand of performance and expansibility of the large scale Web GIS, and some main aspects
which affect Web GIS's performance have been tested, including layer's amount, raster data's compress, pyramidal
storage plan, database optimization, disk array, and cache plan. With the analysis of the tests, we can form strategies to
satisfy different environments and demands.
Forward Looking Infra-Red (FLIR) image segmentation is crucial for Automatic Target Recognition (ATR). This paper presents a thresholding method for image segmentation by performing fuzzy partition on a two-dimensional (2-D) histogram based on maximum entropy principle. We combine the original image with its smooth image to form a binary set, called a "generalized image", and the histogram of the generalized image is a 2-D histogram. In order to adequately utilize the intrinsic information of the FLIR image, we adopt a newly defined fuzzy partition of two fuzzy sets, dark and bright, basing on 2-D histogram. Also we define the corresponding 2-D membership function, which represents the membership of darkness and brightness for each element in the binary set, respectively. The entropy is used as a measure of fuzziness. Based on the Shannon function, we define a 2-D fuzzy entropy. The total fuzzy entropy is the sum of the entropy of each block. Therefore, the fuzzy region can be determined by maximizing the total fuzzy entropy. A genetic algorithm is employed to find the optimal combination of all the fuzzy parameters. Experiment results show that the proposed method gives good performance.