Image segmentation is the division of an image into different regions, each having certain properties. It is the first step of image analysis which aims at either a description of an image or a classification of the image if a class label is meaningful. An example of the former is the description of an office scene. An example of the latter is the classification of the image of a cancerous cell. Image segmentation is a critical component of an image recognition system because errors in segmentation might propagate to feature extraction and classification.