Firstly we need to know about several questions before the vectorization:
- What’s vectorization?
It is to convert the raster data to vector data.
- Why do we need to make vectorization?
Compared with the raster data, the vector data is with compact data structure, low redundancy, is conducive to the network and search analysis, and has good display quality with high precision, so we need to make vectorization in some application analysis.
- What method do we use for vectorization? What conditions are they suitable for?
Thera are two methods: semiautomatically tracing vectorization and automatically tracing vectorization.
- Semiautomatically tracing vectorization is the interactive vectorization mode; trace each lines of the raster data manually, but if the line object has better display effect, the system will automatically trace the line until it can’t trace, then you need to trace manually continuously, in this way you can interactively digitize each line. That applies to the contour map, the drainage map, the road network map and other maps with more line objects.
- Automatically tracing vectorization is completed by the system fully automatically, which is suitable the condition that the line quality is high and the features are clear.
- What’s the process of vectorization?
Currently, in Object Operations>Vectorization, it provides several operation tools for vectorizing lines/regions, which can help completing vectorization work better.
After knowing above four questions, you will know more about vectorization. In this topic, it will use the contour vectorization example to introduce how to use the vectorization tools in iDesktop.
It mainly includes two parts: