To detect text over a wide range of font sizes, the above steps are first applied to a pyramid of images generated from the input image, and then the boxes formed at each resolution level of the pyramid are fused at the image in the original resolution level. Third, text is extracted by cleaning up the background and binarizing the detected text strings. Finally, better text bounding boxes are generated by using the binarized text as strokes. Text is then cleaned and binarized from these new boxes. If the text is of an OCR-recognizable font, it is passed through a commercial OCR engine for recognition.
All parameters remain the same for all the experiments.
This is joint work with Victor Wu and Edward Riseman.