Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1990-09-27
1991-08-06
Kostak, Victor R.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358135, H04N 713
Patent
active
050382098
ABSTRACT:
A buffer/quantizer controller in a video coder utilizes the average quantization step size employed for the previous frame, the average number of bits produced per pel by the video coder for the image contained in the previous frame and current frame buffer fullness level to obtain an indication of image complexity. A target current frame quantization step size to be employed by the video coder in encoding a current frame is based on the indication of image complexity. Optionally, the target frame quantization step size is adjusted by a mapping procedure, at a predetermined intervals within each frame period, to account for the current buffer fullness. The map employed by the mapping procedure is adjusted in accordance with the target frame quantization step size.
REFERENCES:
patent: 4672441 (1987-06-01), Hoelzlwimmer et al.
patent: 4689672 (1987-08-01), Furukawa et al.
patent: 4941043 (1990-07-01), Jass
patent: 4958226 (1990-09-01), Haskell et al.
"Draft Revision of Recommendation H.261 Video Codec for Audiovisual Services at px64 kbit/s", Source: WP XV/1, CCITT, Study Group XV, Geneva, Jul. 16-27, 1990.
"Description of Ref. Model 8 (RM8)", Source: Specialist Group on coding for Visual Telephony, CCITT SGXV, Working Party XV/4, Document 525, 1989.
"a Multiprocessor Based Low Bitrate Video Codec Architecture and a Well-Adapted Two Phase Software Coding Strategy", T. Kummerow, et al., SPIE, vol. 1199 Visual Comm. and Image Processing IV (1989).
"A Low-Bit-Rate Interframe Coder for Videotelephone", B. G. Haskell, et al., Bell System Technical Journal, vol. 54, No. 8, 1975.
"Fixed and Adaptive Predictors for Hybrid Predictive/Transform Coding", S. Ericsson, IEEE Transactions on Communications, vol. Com-33, No. 12, Dec. 1985.
AT&T Bell Laboratories
Kostak Victor R.
Stafford Thomas
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