Structural description of water basins from Landsat imagery using multi-scale image relevance function

摘要

Conventional methods for cartographic shape representation of objects from satellite images are usually inaccurate and will provide only a rough shape description if they are to work in a fully automated mode. For example, existing algorithms for skeletal thinning fail to provide a correctly shaped skeleton if the input images contain noise or the objects of interest are sparse and exhibit discontinuities. The proposed method for extraction of skeletons of 2-D objects is based on an efficient algorithm for multi-scale structural analysis of images obtained from satellite data. The form and topology of hydrological objects, such as rivers and lakes, can be extracted by applying a multi-scale relevance function in a quick, reliable and scale-independent way. The description of objects is obtained in the form of piecewise linear skeletons (multi-scale structural graph) and includes local scales at graph vertices, which correspond to local maxima of the relevance function. The experimental test results using Landsat-7 images show good accuracy of the relevance function approach and its potential for fully automated hydrographic mapping.