Patent US4745474A successfully refreshed from Google Patents.
US4745474A
Expired / Lapsed
US
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Two resolution level DPCM system
Assignee: General Electric Co
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Filing: 1987-04-17
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Granted: 1988-05-17
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Expires: 2007-04-17
Abstract
Abstract A digital television transmitter has a buffer that receives a low resolution low pass filtered signal. A high resolution high pass filtered signal is applied to the buffer only when the buffer can accept it without overflowing. A digital television receiver receives a digital television picture signal and preferably a transmitter buffer occupancy state signal. A low resolution low pass filtered signal is applied to an adder. A high resolution high pass filtered signal is applied to the adder when the buffer state is low and also when it is intermediate and no substantial motion is present. The transmitter and receiver are useful in video teleconferencing.
Inventors
- 👤 Leonard N. Schiff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:18
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/10; H04N19/134; H04N19/146; H04N19/152; H04N19/102; H04N19/124; H04N19/50; H04N19/503
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
76 words
Apparatus for transmitting a digital television picture signal comprising: a buffer having a first output means for providing said digital television picture signal; means for providing first data to said buffer representing a low resolution low pass filtered version of said picture; and means for providing second data to said buffer, only when said buffer can accept said second data without overflowing, said second data representing a high pass filtered high resolution version of said picture.
Claim 2
Dependent Claim
76 words
Apparatus for transmitting a digital television picture signal comprising: a buffer having a first output means for providing said digital television picture signal; means for providing first data to said buffer representing a low resolution low pass filtered version of said picture; and means for providing second data to said buffer, only when said buffer can accept said second data without overflowing, said second data representing a high pass filtered high resolution version of said picture.
Claim 3
Dependent Claim
35 words
The apparatus of claim 1, wherein said buffer further comprises a second output means for providing a signal to said means for providing second data representing high, intermediate, and low occupancy states of said buffer.
Claim 4
Dependent Claim
21 words
The apparatus of claim 1, wherein said first output means also provides code words representing the occupancy state of said buffer.
Claim 5
Dependent Claim
30 words
The apparatus of claim 1, wherein said means for providing first data comprises a digitizer, a low pass filter coupled to said digitizer, and a subsampler coupled to said filter.
Claim 6
Dependent Claim
29 words
The apparatus of claim 1, wherein said means for providing second data comprises an interpolator coupled to said subsampler and a subtractor coupled to said digitizer and said interpolator.
Claim 7
Dependent Claim
25 words
The apparatus of claim 1, wherein said means for providing first data further provides a motion indicating signal to said means for providing second data.
Claim 8
Dependent Claim
56 words
The apparatus of claim 6, wherein said means for providing second data provides said high resolution version when said buffer occupancy is low and also when intermediate and no substantial motion is present, provides a unique code word when said occupancy is high, and provides zeroes when said occupancy is intermediate and substantial motion is present.
Claim 9
Dependent Claim
19 words
The apparatus of claim 1, wherein each of said means for providing comprises a differential pulse code modulation loop.
Claim 10
Dependent Claim
19 words
The apparatus of claim 8, wherein said loop of said means for providing first data comprises an adaptive loop.
Claim 11
Dependent Claim
42 words
The apparatus of claim 8, wherein said adaptive loop comprises a frame store and switch coupled thereto providing a one frame delayed predicted signal when there is no substantial motion and a one pixel delayed predicted signal when there is substantial motion.
Claim 12
Dependent Claim
19 words
The apparatus of claim 1, wherein each of said means for providing comprises an encoder coupled to said buffer.
Claim 13
Dependent Claim
16 words
The apparatus of claim 11, wherein each of said encoders comprises a Huffman and run-length encoder.
Claim 14
Dependent Claim
19 words
The apparatus of claim 11, wherein said second providing means encoder provides zeroes when said buffer occupancy is high.
Claim 15
Dependent Claim
154 words
Apparatus for receiving a digital television picture signal and a transmitter buffer occupancy state signal, said apparatus comprising: a buffer having input means for receiving said signals, and a first output means for providing first data representing a low resolution low pass filtered version of said picture, and second output means for providing a high pass high resolution version of said picture, and a third output means providing the buffer state signal; an adder; means, coupled to said first output means and to said adder, for supplying said first data to said adder and a motion indicator signal; means, coupled to said second and third output means, to said adder, and to said first supplying means, to receive said motion indicator signal and said buffer state signal and for supplying to said adder the second data when the transmitter buffer state signal is low and also when intermediate and no substantial motion is present.
Claim 16
Dependent Claim
154 words
Apparatus for receiving a digital television picture signal and a transmitter buffer occupancy state signal, said apparatus comprising: a buffer having input means for receiving said signals, and a first output means for providing first data representing a low resolution low pass filtered version of said picture, and second output means for providing a high pass high resolution version of said picture, and a third output means providing the buffer state signal; an adder; means, coupled to said first output means and to said adder, for supplying said first data to said adder and a motion indicator signal; means, coupled to said second and third output means, to said adder, and to said first supplying means, to receive said motion indicator signal and said buffer state signal and for supplying to said adder the second data when the transmitter buffer state signal is low and also when intermediate and no substantial motion is present.
Claim 17
Dependent Claim
16 words
The apparatus of claim 14, further comprising a digital to analog converter coupled to said adder.
Claim 18
Dependent Claim
19 words
The apparatus of claim 14, wherein each of said supplying means comprises an inverse differential pulse code modulation loop.
Claim 19
Dependent Claim
15 words
The apparatus of claim 16, wherein said first supplying means loop comprises an adaptive loop.
Claim 20
Dependent Claim
43 words
The apparatus of claim 17, wherein said adaptive loop comprises a frame store and a switch coupled thereto providing a one frame delayed predicted signal when there is no substantial motion and a one pixel delayed predicted signal when there is substantial motion.
Claim 21
Dependent Claim
64 words
Apparatus for receiving a digital television picture signal, said apparatus comprising: a first inverse digital pulse code modulation loop for receiving first data representing a low resolution low pass filtered version of said picture; a second inverse digital pulse code modulation loop for receiving second data representing a high resolution high pass filtered version of said picture; and an adder coupled to said loops.
Claim 22
Dependent Claim
64 words
Apparatus for receiving a digital television picture signal, said apparatus comprising: a first inverse digital pulse code modulation loop for receiving first data representing a low resolution low pass filtered version of said picture; a second inverse digital pulse code modulation loop for receiving second data representing a high resolution high pass filtered version of said picture; and an adder coupled to said loops.
Claim 23
Dependent Claim
16 words
The apparatus of claim 19, further comprising a digital to analog converter coupled to said adder.
Claim 24
Dependent Claim
13 words
The apparatus of claim 19, wherein said first loop comprises an adaptive loop.
Claim 25
Dependent Claim
43 words
The apparatus of claim 21, wherein said adaptive loop comprises a frame store and a switch coupled thereto providing a one frame delayed predicted signal when there is no substantial motion and a one pixel delayed predicted signal when there is substantial motion.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |