A Survey of Thresholding Techniques over Images

This paper presented a comprehensive survey of image thresholding methodologies and categorise them under a uniform notation, indicate their differences or similarities, and finally as a basis for performance comparison. Images have been categorised into six groups according to the information they are exploiting, such as, histogram shape-based methods, clusteringbased methods, entropy-based methods, object attribute-based methods, spatial methods and local methods. In total 44 image binarisation methods are summarised.