Zoom-Invariant Vision of Figural Shape: The Mathematics of Cores
Stephen M. Pizer, David H. Eberly, Bryan S. Morse, Daniel Fritsch · Carolina Digital Repository (University of North Carolina at Chapel Hill) · 1996
Believing that figural zoom invariance and the cross-figural boundary linking implied by medial loci are important aspects of object shape, we present the mathematics of and algorithms for the extraction of medial loci directly from image intensities. The medial loci called cores are defined as generalized maxima in scale space of a form of medial information that is invariant to translation, rotation, and in particular, zoom. These loci are very insensitive to image disturbances, in strong contrast to previously available medial loci, as demonstrated in a companion paper. Core-related geometric properties and image object representations are laid out which, together with the aforementioned insensitivities, allow the core to be used effectively for a variety of image analysis objectives. 3 SYMBOLS s r q , , Greek letter, standing for a scalar variable. Italic. Roman (italic) letters, upper case or lower case, may also be used for variables. r r x, x Roman or Greek letter with arr...