Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1975-10-20
1977-09-27
Sloyan, Thomas J.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
325 38B, H04N 712
Patent
active
040515303
ABSTRACT:
An input video signal is fed to a substracter wherein a difference is taken between the input and the output from a frame memory to provide a difference signal, the magnitude of which is controlled by a magnitude adjuster. The controlled output is then fed to a threshold circuit, from which a significant difference signal is derived which has a magnitude above a given level. The significant difference signal is quantized by an encoder into a code having a reduced number of bits as compared with the inputted significant difference signal. The quantized code is written into a buffer memory, and is read out therefrom at a uniform bit rate to a transmission line. A sum of a signal indicative of the representative level of the quantized code from the encoder and the output of the frame memory is formed in an adder, and the sum signal is written into the frame memory and read out subsequently or after one frame. The occupancy of the buffer memory is detected to provide a control over the magnitude adjuster in accordance with the detected value so as to prevent an overflow from the buffer memory. A signal to refresh the frame memory located on the receiving side is transmitted by writing the output of the adder into the buffer memory after switching from the output of the encoder to the output of the adder.
REFERENCES:
patent: 3562744 (1971-02-01), Howlett
Candy et al., "Transmitting Television as Clusters of--," Bell System Technical Journal, vol. 50, No. 6, 7/71.
Kanaya Fumio
Kuroda Hideo
Nippon Telegraph and Telephone Public Corporation
Sloyan Thomas J.
LandOfFree
Frame-to-frame coding system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Frame-to-frame coding system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frame-to-frame coding system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1819299