Edward J Bowen

US Patent:

43896723, Jun 21, 1983

Filed:

Feb 2, 1981

Appl. No.:

6/230458

Inventors:

Edward G. Bowen - Laurence Harbor NJ
Arun N. Netravali - Westfield NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H04N 712

US Classification:

358160

Abstract:

A pseudo-gray scale signal obtained by comparing the intensity values of elements of a picture with a series of spatially dependent threshold values is processed for display on a multilevel device. Generally, an estimate of the intensity value of each pel is formed as a joint function of the display words which make up the pseudo-gray scale signal and an indication of the threshold value associated with the pel. In one embodiment, the display words and threshold values are used to select appropriate stored intensity values obtained from representative pictures. Alternatively, the estimates are derived recursively using display words and threshold values for a neighborhood near the pel being processed.