Notice: All the software and source code are only used for research purpose. Some third-party libraries are used in our work, and anyone who uses our code must respect their copyrights. If you use the software or source code, please refer to the following paper C. Yi and Y. Tian. Text String Detection from Natural Scenes by Structure-based Partition and Grouping. In IEEE Transactions on Image Processing (TIP), Vol. 20, Issue 9, pp.2594-2605, 2011.