# Image Segmentation

Since blob analysis is fundamentally a process of analyzing the properties of a closed shape, before blob analysis can be performed on an image, the image must be segmented into those pixels that make up the blob being analyzed, and those pixels that are part of the background.

In general, all images that are used for blob analysis start out as grey-scale images of scenes. While it might be easy for a human observer to identify blobs or objects within the scene, before blob analysis can analyze the image, each pixel in the image must be assigned as an object pixel or a background pixel. Typically object pixels are assigned a value of 1 while background pixels are assigned a value of 0.

A number of techniques can be used to segment images into object pixels and background pixels. The following sections describe these techniques.