Recognizing the black block symbols in topographic map by numeric recognition method
Li Wen · Engineering of Surveying and Mapping · 2004
It is much difficult to digitize the black block symbols by hand work. In the paper, based on mathematical morphology, the rapidly and efficiently automatic recognition for the black blocks symbols in topographic maps is realized. On the one hand, scanned map is eroded and dilated. On the other hand, numerical value transformation is imposed in the image processing.