Enhanced X-ray imaging of spheroids: an O(n) algorithm for characterizing convex blobs

A simple O(n) algorithm to find the least squares circular fit of a tabulated function is presented. A demonstration of the algorithm's utility is provided by the analysis of a set of digitized band-filtered images of a radiograph of a common grapefruit. The application of this method of image understanding to the early radiographic detection and analysis of cancer (coin lesions) is proposed.