Method and system for bandwidth-compressed transmission of a video signal in the NTSC system
AssigneeFujitsu Limited
InventorsTakamoto Kojima, Mitsuo Ishii
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Abstract
Bandwidth-compressed transmission of an NTSC-type video signal is performed by converting the analog composite NTSC signals to digital signals and then orthonormally transforming the digital signals corresponding to each horizontal line period of the composite video signal, in the line direction. The transformed, digital signals then are processed to obtain the sum and difference thereof, for each corresponding horizontal line period with respect to those transformed digital signals corresponding to the next preceding horizontal line period. The sum and difference signals then are predictively coded and sequentially transmitted.
Claims21
A system for bandwidth-compressed transmission of NTSC video signals, comprising:
- input means for supplying a composite NTSC signal to be transmitted,
- means connected to said input means for converting the supplied composite NTSC video signal to corresponding digital signals, and
- means for orthonormally transforming said digital signals;
- means responsive to said transformed digital signals for producing sum and difference signals as to each horizontal line period of the composite signal with respect to the respectively next preceding horizontal line period thereof,
- whereby said sum and difference signals respectively correspond to luminance and chrominance signals,
- means receiving the sum and difference signals for separately predictively coding each thereof, and
- means for sequentially transmitting said separately predictively coded sum and difference signals.
A system recited in claim I wherein said orthonormal transforming means produces transformed digital signals of high and low order sequences, and wherein there is further provided:
- mode switch means for alternately selecting said sum and difference signals and supplying said alternately selected signals to said predictive coding means.
A system for transmission and reception of bandwidth-compressed video signals of the NTSC type, comprising:
- a transmitter having supplied thereto a composite NTSC video signal to be compressed in bandwidth and transmitted, including:
- an analog to digital converter for converting the composite NTSC video signal to corresponding digital signals,
- means for orthonormally transforming said digital signals and producing transformed digital output signals,
- means for producing sum and difference digital signals of the transformed digital signals corresponding to a given horizontal line period of the composite video signal with respect to the transformed digital signals corresponding to the respectively next preceding horizontal line period of the composite video signal,
- whereby said sum and difference signals respectively correspond to luminance and chrominance signals,
- means for predictively coding said sum and difference signals, and
- means for supplying the predictively coded sum and difference signals for transmission to a receiver;
- and a receiver incluing:
- means for receiving and decoding the signals transmitted by the transmitter to provide decoded digital signals,
- means for inversely orthonormally transforming the decoded digital signals to produce digital output signals corresponding to the NTSC composite video signal, and
- digital to analog converting means for converting the digital output signals to an analog NTSC composite video signal corresponding to the NTSC composite video signal supplied at the transmitter for transmission.
A system for transmission of bandwidth-compressed video signals of the NTSC type, comprising:
- input means having supplied thereto a composite NTSC video signal to be compressed in bandwidth and transmitted,
- an analog to digital converter for converting the composite NTSC video signal to corresponding digital signals,
- means for orthonormally transforming said digital signals,
- means for producing sum and difference digital signals of the transformed digital signals corresponding to a given horizontal line period of the composite video signal with respect to the transformed digital signals for the respectively next preceding horizontal line period of the composite video signal,
- whereby said sum and difference signals respectively correspond to luminance and chrominance signals, and
- means for separately predictively coding said sum and difference signals for bandwidth-compression and transmission.
A receiver for bandwidth-compressed, transmitted video signals wherein a composite NTSC video signal prior to transmission is converted to digital form and orthonormally transformed and the sum and difference signals of the transformed digital signals corresponding to successive horizontal line periods of the composite video signal with respect to the respectively next preceding horizontal line periods, are separately predictively coded for bandwidth compression and sequential transmission, whereby said sum and difference signals respectively correspond to luminance and chrominance signals, comprising:
- means for receiving and decoding the signals transmitted by the transmitter to provide decoded digital signals,
- means for inversely orthonormally transforming the decoded digital signals to produce digital output signals corresponding to the NTSC composite video signal, and
- digital to analog converting means for converting the digital output signals to an analog NTSC composite video signal corresponding to the NTSC composite video signal supplied at the transmitter for transmission.
A method for bandwidth-compressed transmission of NTSC video signals, comprising:
- supplying a composite NTSC signal to be transmitted,
- producing sum and difference signals as to each horizontal line period of the composite signal with respect to the respectively next preceding horizontal line period thereof,
- whereby said sum and difference signals respectively correspond to luminance and chrominance signals,
- separately predictively coding the sum and difference signals, and
- sequentially transmitting the separately predictively coded sum and difference signals.
A method for transmission and reception of bandwidth-compressed video signals of the NTSC type, comprising:
- supplying a composite NTSC video signal to be compressed in bandwidth and transmitted,
- converting the composite NTSC video signal to corresponding digital signals,
- orthonormally transforming said digital signals and producing transformed digital output signals,
- producing sum and difference digital signals of the transformed digital signals corresponding to a given horizontal line period of the composite video signal with respect to the transformed digital signals for the respectively next preceding horizontal line period of the composite video signal,
- whereby said sum and difference signals respectively correspond to luminance and chrominance signals,
- separately predictively coding said sum and difference signals, and
- sequentially transmitting the separately predictively coded sum and difference signals, said method further including
- receiving and decoding the transmitted signals to provide decoded digital signals,
- inversely orthonormally transforming the decoded digital signals to produce digital output signals corresponding to the NTSC composite video signal, and
- converting the digital output signals to an analog NTSC composite video signal corresponding to the NTSC composite video signal supplied for transmission.
Dependencies are inferred from the claim text.