14 research outputs found
Recognizing some geometrical objects from a discrete set of polygons
This paper presents a post - processing method for extracting polygons after vectorization processing. These polygons are used for a Spatial Data Type of Geographic Information Systems or for recognizing primitive objects included in technical drawings. We propose the semi - automatic searching method for extrating from a set of polylines to a polygon surrounding a given point. This method is based on the depth searching strategy. Then we give a measure fitting polygons with primitive geometrical objects. In fact, the paper makes a deal with the applying of global statistical and geometrical invariants for reconizing planar objects. Nhận dạng một số đối tượng hình học từ các tập đường gấp khúc rời rạ
An examination of techniques for raster-to-vector process and implementation of software package for automatic map data entry-mapscan
The majority of commonly used manipulative techniques in computer-assisted cartography continue to require that the data be in vector format. This situation has recently precipitated the the requirement for fast techniques for converting digital cartographic data from raster to vector format for processing. This article concerns with examining the states in theses conversion techniques. In part one, algorithms to perform all phases of the raster-to-vector process are systematically outlined, and then compared in the general term. Part two will describe the package for automatic map data entry MapScan, the algorithms implemented in which are based on the fast techniques for converting map raster data to vector format. With MapScan users are able to move printed maps or drawing into a mapping system much more quickly and easily compared to using traditional digitizer techniques
Kết hợp các phép toán hình thái học và làm mánh để nâng cao chất lượng ảnh đường nét
This paper present a method of using morphology operations such as Dilation. Erosion and thinning technique for improving feature images. In general, the morphology operations are used for increasing or reducing the thickness of lines, smoothing contours or filling holes in images. Unfortunately, the erosion operation creates dot lines. In order to overcome this shortcoming, we use the dilation operation and thinning technique step by step. This approach is useful for reducing the thickness of lines and keeps the connectness of lines. The first points of LOOP are suitable chosen for process speed. The paper also shows kinds of maps that can be vectorized and have been tested by the software package MAPSCAN developed in the Department of Pattern Recognition and Knowledge Engineering such as: - Topography, hydrography and transport maps etc... - Technical, designing and electronic circle drawings, finger images etc..
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505 tr. : minh hoạ ; 27 cm