Ling ling Feng, Guo qing Qi
An algorithm for extracting information from meteorological facsimile maps and transform the map into vector format is proposed. The algorithm contains two parts. The first one is annotation information extraction method based on the regular pattern of position and angle, the second part is isobars vectorization based on tracking and filtering. As the annotations change with latitude line, relevant characters can be extracted on the basis of removing the base map and then thinning the isobars. After removing noise and connecting broken isobars, seamless and smooth isobars are extracted by means of - filtering. Then extracted isobars are approximated by polygonal lines to compress the data of isobars. Experiments show that the proposed algorithm can extract annotation and vectorize isobars.