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公开(公告)号：US3571807A
公开(公告)日：1971-03-23
申请号：US3571807D
申请日：1968-11-13
Applicant: BELL TELEPHONE LABOR INC
Inventor： CANDY JAMES C , MOUNTS FRANK W
CPC classification number: H04N19/507 , H04N19/503
Abstract: A redundancy reduction system is described for use with signals such as video signals which have frame-to-frame redundancy. An entire frame of samples from the signal is stored in a frame memory. Each new sample from the signal is compared with its corresponding stored sample having the same time position within the frame. If a significant difference is found to exist between the two samples, the new sample is placed into the frame memory replacing the old sample, and in addition an identification or flag signal is placed into a flag memory at a corresponding address. A searching circuit scans the flag memory and detects those address locations which have been marked by a flag or identification signal. In response to detecting a flag at a particular address location the sample stored in the frame memory at that address location is read out of the frame memory and coupled to a digital transmitter for transmission to a receiving location.
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2.发明授权
公开(公告)号：US3436471A
公开(公告)日：1969-04-01
申请号：US3436471D
申请日：1966-06-01
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W , PRASADA BIRENDRA
CPC classification number: H04J3/17 , H04N7/0855
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公开(公告)号：US3090008A
公开(公告)日：1963-05-14
申请号：US6452460
申请日：1960-10-24
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W
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4.发明授权
公开(公告)号：US3609244A
公开(公告)日：1971-09-28
申请号：US3609244D
申请日：1969-12-18
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W
CPC classification number: H04N19/152 , H04N19/50 , H04N19/503
Abstract: The amplitude of a sample from a signal having frame-to-frame redundancy is transmitted only if the amplitude differs significantly from the amplitude of a corresponding sample having the same time position in a previous frame interval. An address word is assigned to each sample to indicate the position of that sample within a group of samples. Group synchronization is maintained between the transmitter and receiver by forcibly transmitting the last sample in each group whether or not that sample represents a significant change. The value of each address word indicates the length of the interval between the location of its respective sample and the end of the group. Only those bits of an address word which are necessary to locate the sample in the interval between the last-transmitted sample and the end of the group are transmitted to the receiving location. A control word whose bit values indicate which bits of the next address word must be transmitted is developed from each address word and is stored until the next selected address word in response to an indication that its corresponding address word has been selected for transmission.
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5.发明授权
公开(公告)号：US3584145A
公开(公告)日：1971-06-08
申请号：US3584145D
申请日：1968-12-23
Applicant: BELL TELEPHONE LABOR INC
Inventor： CUTLER CASSIUS C , MOUNTS FRANK W
IPC: H04J3/16 , H04J3/18 , H04N7/36 , H04N21/2365 , H04N21/434 , H04N7/12
CPC classification number: H04N21/4347 , H04J3/1688 , H04J3/18 , H04N19/503 , H04N21/2365
Abstract: Video signals from several sources are processed by a plurality of redundancy reduction data compressors and combined in an asynchronous time division multiplexing system. Each redundancy reduction data compressor couples to its buffer memory only those video samples which differ by an amount greater than a threshold level from the video samples previously stored in a reference frame memory. A count of the number of frames stored in the buffer memory is utilized by a control logic circuit as a first condition to determine the priority of connecting each redundancy reduction data compressor to a transmission channel. When the number of frames in each buffer memory is equal, the control logic circuit utilizes a count of the number of samples stored in the buffer memory as a second condition to determine the priority for connection to the transmission channel. Several threshold circuits are provided in each of the redundancy reduction data compressors. The particular one chosen for use by the control logic circuit depends on the use that the data compressor has made of the transmission channel.
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Patent Agency Ranking
公开(公告)号：US3553361A
公开(公告)日：1971-01-05
申请号：US3553361D
申请日：1969-04-30
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W
CPC classification number: H04N19/152 , H04N19/50 , H04N19/503
Abstract: A redundancy reduction system is described for processing video signals by comparing each amplitude sample derived from the video signal with a stored sample corresponding to the amplitude at the same spatial point location in a previous video frame. If a significant difference exists between the new sample and the stored sample, the amplitude for the new sample is selected for transmission to a receiving location. An address word is generated with each sample to indicate the location of that sample in a video line. The address word for a sample is transmitted with the amplitude only when the transmitted sample follows a sample which has not been selected for transmission. A flag word whose value is distinguishable from all amplitude values is transmitted to indicate the end of a run of amplitude values. A synchronization word is transmitted between the samples in adjacent video lines in order to maintain line synchronization with the receiver.
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公开(公告)号：US3580999A
公开(公告)日：1971-05-25
申请号：US3580999D
申请日：1968-12-23
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W
CPC classification number: H04N19/152 , H04N19/124 , H04N19/50 , H04N19/503
Abstract: A redundancy reduction data compressor is described for processing a video signal having time subintervals called frames, the amplitude level of which signal is an indication of the luminance level in a scene being viewed. An entire frame of samples from the signal is stored in a frame memory. Each new sample from the signal is compared with its corresponding stored sample having the same time position within the frame. If the new sample is found to differ from the stored sample by more than a threshold level, the new sample is stored in a buffer memory to await transmission over a transmission channel. The threshold level is a function of the luminance level of the new sample and number of samples stored in the buffer memory, such that a sample from the high brightness region of the picture and/or a larger number of samples in the buffer memory result in a larger threshold level.
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公开(公告)号：US3571505A
公开(公告)日：1971-03-16
申请号：US3571505D
申请日：1968-08-02
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W
IPC: H04B1/66 , H04L23/00 , H04N7/12 , H04N7/36 , H04N21/236 , H04N21/434 , H04N5/38 , H04N5/44
CPC classification number: H04N21/434 , H04B1/66 , H04N19/503 , H04N21/236
Abstract: A redundancy reduction system is described for processing video signals by comparing each digital word derived from the video signal amplitude for each picture element with a stored word corresponding to the amplitude for that picture element in a previous frame. Only if a significant difference exists between the new word and the previously stored word is the new amplitude word transmitted to the receiving location. The position of the transmitted amplitude word in the video frame is indicated to the receiver by an address word which is also transmitted. The address word indicates only the relative position of a picture element in the active region of the horizontal scanning line. The first picture element of the video frame is provided with a unique address word and in addition, the first picture element of each line is forced to be transmitted whether or not a significant difference exists between the new amplitude and previously stored amplitude. The received amplitude and address words are stored before processing in a receiving buffer memory. Initial readout of the receiving buffer memory is prohibited until a sufficient number of words have been received in order to insure proper synchronization with this unique method of addressing.
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9.发明授权
公开(公告)号：US3553362A
公开(公告)日：1971-01-05
申请号：US3553362D
申请日：1969-04-30
Applicant: BELL TELEPHONE LABOR INC
Inventor： MOUNTS FRANK W
CPC classification number: H04B1/66 , H04N19/152 , H04N19/50 , H04N19/503
Abstract: A redundancy reduction system is described for processing video signals by comparing each amplitude sample derived from the video signal with a stored sample corresponding to the amplitude at the same spatial point location in a previous video frame. If a significant difference exists between the new sample and the stored sample, the amplitude for the new sample is selected for transmission to a receiving location. An address word is generated with each sample to indicate the location of that sample in a video line. When samples in two or more adjacent spatial point locations are selected for transmission, only the address word corresponding to the first location is transmitted. A code word, whose value indicates the number of samples in addition to the first which are to be associated with this single address word, is transmitted prior to the amplitude values for these additional samples. A synchronization word is transmitted between the samples in adjacent video lines in order to maintain line synchronization with the receiver.
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10.发明授权
公开(公告)号：US3609552A
公开(公告)日：1971-09-28
申请号：US3609552D
申请日：1969-08-20
Applicant: BELL TELEPHONE LABOR INC
Inventor： LIMB JOHN O , MOUNTS FRANK W
CPC classification number: H03M3/04
Abstract: A differential pulse code communication system is disclosed which digitally accumulates the difference signal in order to eliminate the matching problem inherent in prior art systems. In the transmitter the difference signals are digitally accumulated and converted to analog form for subtraction from the input signal, and at the receiver the difference signal is accumulated before it is converted to analog form to reconstruct the input signal.
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