A comprehensive survey on shadow detection techniques

Shadow cause some unwanted change in computer vision and image analysis. Shadow leads to problems in extraction, segmentation of object and recognition due to the misclassification of shadow points as foreground or object points. So, the detection of shadow is of broad interest in computer vision. Due to the alteration in illumination of the background and similarity between appearance of the objects and background, accurate detection of shadow is difficult. Lots of researches have been done on shadow detection to address these challenges. For different environmental conditions many algorithms and techniques have been developed to detect shadow from the images. This paper aims to provide comprehensive survey of various shadow detection techniques and also includes comparative analysis of these techniques.