A New Method for Shading Removal and Binarization of Documents Acquired with Portable Digital Cameras

Photo documents, documents digitized with portable digital cameras, often are affected by non-uniform shading. This paper proposes a new method to remove the shade of document images captured with digital cameras followed by a new binarization algorithm. This method is able to automatically work with images of different resolutions and lighting patterns without any parameter adjustment. The proposed method was tested with 300 color camera documents, 20 synthetic images with ground truth lighting pattern and grayscale images of the dataset of CBDAR 2007 dewarping contest. The results show that the new algorithm proposed here works in a wide variety of scenarios and keeps the paper texture of the original document.