An overview of existing literature on document skew detection

In the proposed paper we present an overview of the existing methods of skew estimation. Skew estimation is one of the major prepossessing task in document image. In this article we present the evaluation of skew estimation process from the very beginning of classical methods to the latest Artificial Intelligence methods like Convolutions Neural Network(CNN). A wide range of database which have been used by the researcher throughout the decades for the skew estimation process is also discussed in this paper. A clear understanding of different types of skew is being discussed in this article. We categorically discussed different existing methods of skew estimation in brief. We also present a comparative studies on different existing methods of skew estimation. This article will help the researchers who intend to do research on this field.