05136377 is referenced by 104 patents and cites 6 patents.

A quantizer, with quantization control that is sensitive to input signal characteristics and to output buffer fullness responds to an input signal that is divided into blocks and DCT transformed. The transformed signal is analyzed to develop a brightness correction and to evaluate the texture of the image and the change in texture in the image. Based on these, and in concert with the human visual perception model, perception threshold signals are created for each subband of the transformed signal. Concurrently, scale factors for each subband of the transformed signal are computed, and a measure of variability in the transformed input signal is calculated. A measure of the fullness of the buffer to which the quantizer sends its encoded results is obtained, and that measure is combined with the calculated signal variability to develop a correction signal. The correction signal modifies the perception threshold signals to develop threshold control signals that are applied to the quantizer. The scale factors are also applied to the quantizer, as well as a global target distortion measure.

Title
Adaptive non-linear quantizer
Application Number
7/626279
Publication Number
5136377
Application Date
December 11, 1990
Publication Date
August 4, 1992
Inventor
Peter H Westerink
Newark
NJ, US
Robert J Safranek
New Providence
NJ, US
Eric D Petajan
Watchung
NJ, US
Arun N Netravali
Westfield
NJ, US
Kim N Matthews
Watchung
NJ, US
Scott C Knauer
Mountainside
NJ, US
James D Johnston
Warren
NJ, US
Agent
Henry T Brendzel
Assignee
AT&T Bell Laboratories
NJ, US
IPC
H04N 7/04
H04N 7/01
H04N 7/12
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