Image segmentation emerges as one of the important fields in image analysis. There are many image segmentation
algorithms in literature and each has its own pros and cons. This paper deals with the cluster based image segmentation methods
as it gives a new way of mathematical pattern to identify regions in an image. The paper presents an extensive review of
clustering algorithms, which includes clustering algorithms and their improved versions. Various extended versions of K-means,
FCM, Gravitational Clustering.