We present a method for unsupervised boundary classijication by producing and analyzing intensity profiles. Each profile is created by sampling an ellipsoidal neighborhood of voxels oriented along the image gradient. The profile is analyzed via non-linear optimization tofind the bestfitting cumulative Gaussian. The parameters of the cumulative Gaussian parameterize the boundary directly yielding (I) extrapolated intensity valuesfor voxels locatedfar inside and outside of the boundary, (2) estimates boundary location and boundary width. For these parameters, intrinsic measures of confidence are established to eliminate low-confidence parameter estimates. Neighborhoods overlap considerably, yielding sufficient high-confidence estimates for a thorough survey of the boundary. Gradient oriented profiles are demonstrated on artijicially generated three-dimensional test data and proved to accurately parameterize and classify the boundary.
Robert J. Tamburo, George D. Stetten