An MRF Model for Binarization of Natural Scene Text

Anand Mishra (1) , Karteek Alahari (2, 3) , C.V. Jawahar (1)

1 CVIT - Center for Visual Information Technology [Hyderabad]
2 LIENS - Laboratoire d'informatique de l'école normale supérieure
3 WILLOW - Models of visual object recognition and scene understanding

Inspired by the success of MRF models for solving object segmentation problems, we formulate the binarization problem in this framework. We represent the pixels in a document image as random variables in an MRF, and introduce a new energy (or cost) function on these variables. Each variable takes a foreground or background label, and the quality of the binarization (or labelling) is determined by the value of the energy function. We minimize the energy function, i.e. find the optimal binarization, using an iterative graph cut scheme. Our model is robust to variations in foreground and background colours as we use a Gaussian Mixture Model in the energy function. In addition, our algorithm is efficient to compute, and adapts to a variety of document images. We show results on word images from the challenging ICDAR 2003 dataset, and compare our performance with previously reported methods. Our approach shows significant improvement in pixel level accuracy as well as OCR accuracy.

Mots clés: Binarization; GMM; Graph Cut; MRF

Domaines: Vision par ordinateur et reconnaissance de formes [cs.CV]

Anand Mishra, Karteek Alahari, C.V. Jawahar. An MRF Model for Binarization of Natural Scene Text. ICDAR - International Conference on Document Analysis and Recognition, Sep 2011, Beijing, China. ⟨10.1109/ICDAR.2011.12⟩. ⟨hal-00817972⟩