A Survey on Image Segmentation and Image Registration

Abstract—Image segmentation is the process of assigning a label to every pixel in an image such that pixels with the same label share certain characteristics. In discontinuity based approach images are partitioned on the basis of abrupt changes in intensity, such as edge detection, line detection and point detection. In similarity based approaches images are partitioned into regions that are similar according to a set of predefined criteria, as for example thresholding, Region Growing, Region Splitting, Region Merging, Watershed algorithm and seeded Watershed algorithm. Image registration algorithms can be classified into intensity-based and feature-based. One of the images is referred to as the reference, source, target and the others are respectively referred to as the target, sensed or subject images. Image registration involves spatially registering the target image(s) to align with the reference image. Intensity-based methods compare intensity patterns in images via correlation metrics, while feature-based methods find correspondence between image features such as points, lines, and contours. Intensity-based methods register entire images or sub-images. If sub-images are registered, centers of corresponding sub images are treated as corresponding feature points. Feature-based methods establish a correspondence between a number of especially distinct points in images. Knowing the correspondence between a number o