Recognition of convex blobs

Abstract Because of the discrete nature of the memory and logic of a digital computer, a digital computer “sees” pictures in cellular form, each cell containing a number that represents the density of the viewed object at that cell. In particular, when the picture is binary, each cell holds a 1 or 0, depending on whether or not the viewed object is projected onto that cell. The convexity of cellular blobs—a restricted class of binary cellular figures—is discussed and defined in terms of the continuous blobs of which the cellular blobs are images. The elements of a theory of convex cellular blobs are given. As an application of the theory, the use of the “minimum-perimeter polygon” in an algorithm for testing the convexity of cellular blobs on a rectangular mosaic is described.