David K Fibush

58185208, Oct 6, 1998

Feb 12, 1996

8/605241

Bozidar Janko - Portland OR
David K. Fibush - Beaverton OR

Tektronix, Inc. - Wilsonville OR

H04N 1700

348192

A method of automatic measurement of compressed video quality superimposes special markings in the active video region of a subset of contiguous frames within a test video sequence. The special markings provide a temporal reference, a spatial reference, a gain/level reference, a measurement code, a test sequence identifier and/or a prior measurement value. The temporal reference is used by a programmable instrument to extract a processed frame from the test video sequence after compression encoding-decoding which is temporally aligned with a reference frame from the test video sequence. The spatial reference is used by the programmable instrument to spatially align the processed frame to the reference frame. The measurement code is used by the programmable instrument to select the appropriate measurement protocol from among a plurality of measurement protocols. In this way video quality measures for a compression encoding-decoding system are determined automatically as a function of the special markings within the test video sequence.

52086666, May 4, 1993

Oct 25, 1991

7/782927

Bob Elkind - Gaston OR
David Fibush - Beaverton OR
Kenneth M. Ainsworth - Aloha OR

Tektronix, Inc. - Wilsonville OR

H04N 1700

358139

Error detection for digital television equipment that strips away the vertical and horizontal intervals of a digital video signal so that only the active picture portion of the digital video signal is determined by a digital test signal generated from the digital video signal. The digital test signal has replaced at a predetermined location in the active picture portion of the digital video signal one or more video data words with data values that represent check word data for the active picture portion. The check word data may be inserted into the beginning of one of the horizontal lines of the active picture portion of the next field, or may be modified and inserted into the end of the last line of the active picture portion of the same field of the digital video signal. A receiving instrument processes the output of the digital television instrument under test to generate active picture check word data. The active picture check word data is compared either with the check word data extracted from the predetermined location in the active picture portion of the digital test signal or with a predetermined value to determine whether there were any digital errors in processing of the digital test signal by the digital television equipment.