In a classification of satellite remote sensing image data, spectral distribution in a feature space is usually used. Mixels caused by class boundaries, however, give miss-classification results. To solve this problem many researchers have tried to extract or to avoid mixels using edge detectors such as spatial frequency filters. In this study, we describes a method to make clear edge information mentioned above. In particular, a new edge detector using Mathematical Morphology algorithm is introduced. Conventional Morphological edge detectors are classified in dilation-type and erosion-type. The dilation-type edge detector is defined by subtraction of the original image from the dilated image. In a similar manner, the erosion-type edge detector is defined by subtraction of the eroded image from the original image. Both dilationtype and erosion-type edge detectors can detect edge information clearly. Their outputs, however, show different gradients depending on the formula and the size of structuring element. From this point of view, a Multi-functional Wide-Narrow Morphological Edge detector (WNED) is introduced. WNED consists of wide range edge detection (WED), narrow range edge detection (NED) and their subtraction. At the first step of WNED, the maximization of dilation- and erosion-type NED are calculated. WED is then calculated. Finally the subtraction of them is calculated. Performance of WNED is shown by applying visible and IR image of Landsat TM data which cover Shonai river and Kiso river, Japan and compared with the results analyzed by conventional formulae. As the results of case study, followings are found. Application of dilation- and erosion-type edge detectors is not sufficient to pick up the weak gradients. Even if the size of structuring element for dilation- and erosion-type ones is increased, undesireble gradients are detected. In contrast to such algorithms, WEND can detect the desired gradients and can delete the spurious edge pixels by subtracting NED gradients from WED gradients.
This study discussed on the implementation of GIS using internet to the routine work of the local government office. Near fufure, if CALS is applied in the local government office, the transportation of map data will be critical for data management. Because the transportation of documents is discussed well in private company now and the methodology is called “intranet”, but the map issue is not discussed.This is the motivation of our study. First we surveyed the work of the all of local government Gifu city's office, and selected the routine work to be fitted for applying GIS using internet.From the result of surveying, we found that the routine work of local government office was divided into two types, one was the section that uses maps that had good accuracy, and the other was the section that did not need accuracy and the map.And we found the routine work for consultation and judging on building or rebuilding the construction is best fitted to GIS using internet.These works often occurred every day, and the works were cooperated not only one section but also many sections.Second we constructed the prototype system for browsing the map data for the routing work on consulting when the constructor plans the house building. As a result, we found that the routine work for consultation and judging on building or rebuilding the construction was carried out by many sections, so the data transportation via internet was effective, and the methodology for implementation was discussed.