04857999 is referenced by 332 patents and cites 17 patents.

A video monitoring system for identifying television broadcast program material such as commercials by extracting characters present in the closed captioned portion of the video signal at line 21, field 1 and comparing the extracted characters to stored characters and recording the occurrence of a match between the extracted characters and the stored characters indicating the presence of specific program material such as a commercial in the broadcast signal. In an alternative embodiment, comparison may be made between a compressed character string formed from extracted characters and a stored compressed character string.

Title
Video monitoring system
Application Number
7/287452
Publication Number
4857999
Application Date
December 20, 1988
Publication Date
August 15, 1989
Inventor
Russell J Welsh
Toronto
CA
Agent
Faegre & Benson
Assignee
PEAC Media Research
CA
IPC
H04N 7/087
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