Research And Implementation Of Automatic Label Placement For Thematic Map Of Three Tone

Due to the continuous development of science and technology,surveying and mapping instruments are more and more advanced,and the amount of data collected in the field is increasing.It is an urgent problem to automatically map a large number of data,reduce manual participation,and shorten the mapping time,in which the automatic configuration of notes is an important step.In recent years,the research on the automatic configuration of map annotation mainly focuses on the ordinary map,while the research on the automatic configuration of map spot annotation in the three tone thematic map is less.This paper is the exploration of the automatic configuration of map spot annotation.In order to solve the problem of large number of patches and more annotations in the process of patch annotation configuration in the thematic map of three tone,the problem of annotation capping and serious conflict is caused.Based on the data of Zhenping county in Shaanxi Province,this paper uses Mapstore software to study the automatic configuration method of spot annotation in thematic map of three tone.The research results are of great significance for speeding up the allocation of spot annotations.The main contents of this paper are as follows(1)Due to the various shapes and different areas of patches,it is difficult to realize the automatic configuration of patch annotations in one way.We need to classify the patches.Different categories correspond to different methods.We use shape factor and area ratio in shape measurement to classify the patches,which are divided into regular patches,irregular patches and small area patches.(2)Different types of spots are automatically configured by different methods.The central point method is adopted for regular spots;the maximum internal rectangle method based on scanning and internal grid method are adopted for irregular spots;the small area spots are annotated outside the spots and genetic algorithm is adopted.(3)Using Mapstore software combined with specific methods to develop the annotation automatic configuration module,select part of the data in Zhenping county of Shaanxi Province for experiment,and verify the annotation results by using the annotation quality evaluation function.This paper studies the method of automatic configuration of spot annotation,selects specific data for experiments,and verifies the research method with experimental data.The conclusion is that the different methods are effective,conform to the rules of annotation configuration,and have strong pertinence.It has achieved great effect in solving the problem of automatic configuration of annotation in thematic map of three tone.