A transformation for extracting new descriptors of shape. With: Symposium on models for the perception of speech and visual form. Collection of papers relating to the symposium

Blum, Harry (1924-87). (1) A transformation for extracting new descriptors of shape. Reproduced typescript. 17, [5]pp. Bedford, MA: Data Sciences Laboratory, Air Force Cambridge Research Laboratories, 1964. 280 x 218 mm. Original printed wrappers. With:

(2) Symposium on models for the perception of speech and visual form. Collection of documents including 21 typed or reproduced abstracts of papers; 11 letters; the preliminary program for the conference; 16-page list of attendees; and related drafts, photocopies, etc. Approx. 100 sheets total. N.p., 1964. 280 x 218 mm. In folder labeled "Symp. on model for perception / Submitted abstracts & papers." Very good.

First Printing. Blum, a specialist in biological and visual shape description, is best known for two key concepts in image processing: The medial axis; i.e., the set of all points on an object having more than one closest point on the object's boundary, and the grassfire transformation; i.e., the computation of the distance from a pixel to the border of a region. He introduced these concepts in his 1964 paper, "A transformation for extracting new descriptors of shape," which was presented at the Air Force Cambridge Research Laboratory's 1964 symposium on models for the perception of speech and visual form. The paper was published three years later in the proceedings of the symposium (1967).

Blum began his work on shape analysis while employed at the AFCRL's Data Sciences Lab, where he worked from 1960 to 1967. Blum came up with the idea for the AFCRL's 1964 symposium and was one of the conference's principal organizers.