A boundary representation and comparison technique for two-dimensional objects

A novel method is provided for the representation and comparison of boundaries of two-dimensional objects. The work builds upon the rotating squares algorithm of Donafee and Maple (2000), a method based upon the marching cubes algorithm of Lorensen and Cline (1987). The rotating squares method for representing and comparing the boundaries of two-dimensional objects differs from standard polygonal approximations of objects in the sense that, though more space is required for data storage, there is no loss of data as is the case with approximations. This work presents a new method for polygonal approximation and details of a hybrid method whereby polygonal approximations are used for initial boundary comparisons and then the exact data is used for further investigation.