US5612748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sub-sample transmission system for improving picture quality in motional picture region of wide-band color picture signal
Assignee: Japan Broadcasting Corp
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Filing: 1995-06-06
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Granted: 1997-03-18
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Expires: 2015-06-06
Abstract
Abstract In the case where a wide-band color picture signal provided for a high-definition television broadcasting is sub-sampled for narrow-band transmission, in comparison with a stationary picture signal which is applied with sub-sampling according to a sampling pattern circulated at every two frames, the color picture signal in motional picture regions, which is conventionally applied with line-offset sub-sampling at every field, has a lowered resolution. To improve the resolution concerned, color difference signals in motional picture regions are applied with inter-field offset sub-sampling together with band-limitation for preventing aliasing distortion accompanied with subsampling and signal processing including interpolation for reproduction, which are effected in a form completed at every frame. As for motional picture regions having small motion, a luminance signal is applied also with similar sub-sampling and similar signal processing. As a result, the overall picture quality of the reproduced motional color picture is improve by signal processing thus adapted for color pictures in motional picture regions.
Inventors
- 👤 Seiichi Gohshi
- 👤 Yoshinori Izumi
- 👤 Masahide Naemura
- 👤 Kouichi Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:25
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/72; H04N11/00; H04N11/04; H04N11/042; H04N11/048; H04N11/24; H04N11/28; H04N7/00; H04N7/015; H04N7/0152; H04N7/12; H04N7/122
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
135 words
A sub-sample transmission method for wide-band color picture signals, comprising the steps of: (a) sampling a wide-band color picture signal in accordance with a sampling pattern which circulates every two frames; (b) determining a motional picture region and a still picture region of said wide-band color picture signal from said sampled wide-band color picture signal; (c) inter-field offset sub-sampling said motional picture region, determined by step (b), to produce a sub-sampled motional picture region, and performing inter-field signal processing on said sub-sampled motional picture region to produce a processed motional color picture signal, wherein said inter-field offset subsampling and said inter-field signal processing are completed in every frame consisting of odd and even fields of said wide-band color picture signal; and (d) offset sub-sample transmitting the processed motional color picture signal produced in step (c).
Claim 2
Dependent Claim
135 words
A sub-sample transmission method for wide-band color picture signals, comprising the steps of: (a) sampling a wide-band color picture signal in accordance with a sampling pattern which circulates every two frames; (b) determining a motional picture region and a still picture region of said wide-band color picture signal from said sampled wide-band color picture signal; (c) inter-field offset sub-sampling said motional picture region, determined by step (b), to produce a sub-sampled motional picture region, and performing inter-field signal processing on said sub-sampled motional picture region to produce a processed motional color picture signal, wherein said inter-field offset subsampling and said inter-field signal processing are completed in every frame consisting of odd and even fields of said wide-band color picture signal; and (d) offset sub-sample transmitting the processed motional color picture signal produced in step (c).
Claim 3
Dependent Claim
73 words
A method as claimed in claim 1, wherein when said processed motional picture signal is transmitted, a vertical frequency band of said processed motional picture signal having a band-width which is substantially one to three times a Nyquist band, corresponding to a sampling frequency in a vertical frequency region, is transmitted with a limited horizontal frequency band, so as to reduce aliasing distortion caused in a reproduced picture by said inter-field offset sub-sampling.
Claim 4
Dependent Claim
59 words
A method as claimed in claim 1, wherein when said processed motional picture signal is transmitted, the picture signal is sampled by a field-offset sub-sampling in which positions of sample points are alternately shifted between adjacent fields, and a signal processing operation, including at least band-limitation of a luminance signal and interpolation of sample values, is completed every frame.
Claim 5
Dependent Claim
77 words
A method as claimed in claim 1, wherein in a color difference signal, for the motional picture region, which is transmitted with a horizontal spatial frequency band which is halved in comparison with that of a luminance signal, (i) an inter-field offset sub-sampling, (ii) a frequency band limitation for preventing an aliasing distortion caused by said sub-sampling of step (i) and (iii) an interpolation in reproduction are completed at every frame consisting of odd and even fields.
Claim 6
Dependent Claim
61 words
A method as claimed in claim 1, wherein when motion in a vertical direction in the motional picture region is below a predetermined threshold, (i) an inter-field offset sub-sampling, (ii) a frequency band limitation for preventing an aliasing distortion caused by said sub-sampling of step (i) and (iii) interpolation in reproduction for a luminance signal are effected by an inter-field processing.
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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) | 2000-03-17 | 2000-09-16 | 2001-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-17 | 2004-09-16 | 2005-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-17 | 2008-09-16 | 2009-03-18 | $7700.00 | Window Closed / Lapsed |