Text extraction and segmentation using opencv and java for android application

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If you are are looking for method to isolate forground text from back ground , i read that the best method till now is SWT (Stroke Width Transform ) , the method is announced on 2010 by Epshtein and others in 2010 you can find the implementation and some description in the following link SWT description and implementation

the method works for any color text on any background , also it works when there is alot of text written in diffirent colors , you can use it as generlized text detection method