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..

Tài liệu hướng dẫn sử dụng hệ quản trị cơ sở dữ liệu ảnh DIMS : [Kết quả nghiên cứu Khoa học]

21 tr

Chương trình nguồn của hệ quản trị cơ sở dữ liệu ảnh DIMS : [Kết quả nghiên cứu Khoa học]

91 tr

Nghiên cứu cơ bản và ứng dụng công nghệ thông tin

505 tr. : minh hoạ ; 27 cm