Note that this paper is from 2010 and thus, while quite influential for its time far from the current state-of-the-art. The stroke width transform method that it introduced is simply not as good as current deep learning-based methods.

If you want to get a (slightly out of date but what can you do, the field is moving very fast) overview see this survey from 2016:

Scene Text Detection and Recognition: Recent Advances and Future Trends http://mclab.eic.hust.edu.cn/UpLoadFiles/Papers/FCS_TextSurv...