A Robust Approach to Extraction of Texts from Camera Captured Images

Sudipto Banerjee, Koustav Mullick, Ujjwal Bhattacharya

Abstract: Here, we present our recent study of a robust but simple approach to extraction of texts from camera-captured images. In the proposed approach, we first identify pixels which are highly specular. Connected components of this set of specular pixels are obtained. Pixels belonging to each such component are separately binarized using the well-known Otsu’s approach. We next apply smoothing on the whole image before obtaining its Canny edge representation. Bounding rectangle of each connected component of the Canny edge image is obtained and multiple components with pairwise overlapping bounding boxes are merged. Otsu’s thresholding technique is applied separately on different parts of input image defined by the resulting bounding boxes. Although Otsu’s thresholding approach does not generally provide acceptable performance on camera captured images, we observed its suitability when applied severally as in the above. The binarized specular components obtained at the initial stage replace the corresponding regions of the latter binarized image. Finally, a set of postprocessing operations is used to remove certain non-text components of the binarized image.