Summary: Randomized Inquiries About Shape;
an Application to Handwritten Digit Recognition
Yali Amit and Donald Geman y
TECHNICAL REPORT NUMBER 401
Department of Statistics
University of Chicago
Chicago, IL 60637
Department of Statistics, University of Chicago, Chicago, IL, 60637; Email: firstname.lastname@example.org.
Supported in part by the ARO under grant DAAL-03-92-G-0322.
yDepartment of Mathematics and Statistics, University of Massachusetts, Amherst, MA 01003;
Email:email@example.com. Supported in part by the NSF under grant DMS-9217655, ONR under
contract N00014-91-J-1021, and ARPA contract MDA972-93-1-0012.
We describe an approach to shape recognition based on asking relational questions
about the arrangement of landmarks, basically localized and oriented boundary seg-
ments. The questions are grouped into highly structured inquiries in the form of a tree.
There are, in fact, many trees, each constructed from training data based on entropy
reduction. The outcome of each tree is not a classi cation but rather a distribution