Three-dimensional (3D) image processing and interpretation is very imp
ortant in many medical and industrial applications. Detection of 3D bo
undaries is an essential step in most of the 3D image analysis tasks.
In this paper a new computational approach to 3D edge detection is pro
posed. Optimality criteria such as signal-to-noise ratio, localization
, and spurious response for zero-crossing-based, rotationally invarian
t 3D step edge detectors are derived. An optimal 3D step edge detector
is obtained by optimizing a penalty function which combines all the t
hree criteria. The closed form solution to the optimization problem yi
elds the optimal detector. The detector is the Laplacian of a rotation
ally invariant function, which has a finite spatial support. The behav
ior of the proposed detector is theoretically analyzed and compared to
that of the 3D Laplacian of Gaussian detector. Experimental results w
ith some synthetic and real images are presented. (C) 1994 Academic Pr
ess, Inc.