Text/graphics segmentation is a fundamental step in engineering drawing images analysis. However, it is hard to handle when texts touch the graphical entities. In this paper, a solving method called 'the shielding method' is proposed. The main idea lies in labeling the basic graphical entities, which are possible touched by texts, in other words, in other words, it is to shield graphical objects in a line drawing image prior to text/graphics segmentation. A usual long line scanning method can be used to detect horizontal and vertical object lines, and then touching characters can be segmented efficiently at a fast speed. For more common situation, a generic object labeling process based on run-based graph is introduced. Test has shown good results of segmentation compared to that without using this method in a drawing with a lot of graphics touching characters.
"Shielding method for segmentation of graphics touching text in engineering drawings", Proc. SPIE 3305, Document Recognition V, (1 April 1998); doi: 10.1117/12.304640; https://doi.org/10.1117/12.304640