US4873573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video signal processing for bandwidth reduction
Assignee: British Broadcasting Corp
•
Filing: 1986-12-23
•
Granted: 1989-10-10
•
Expires: 2006-12-23
Abstract
Abstract At the transmitter a coder includes a motion vector generator providing vectors (MV) describing the movement of individual blocks of pixels. The video signal is 4:1 compressed in bandwidth by pre-filters and a sub-sampling unit to produce a signal (SSH) from which a high-definition image can be re-constructed in the coder and in the decoder. The sampling lattice is shifted in accordance with the motion vectors (MV) which are digitally transmitted along with the compressed bandwidth analogue signal, to enable the samples to be correctly located in the reconstructed image. Poorly correlated moving areas are handled by pure spatial filtering (pre-filter and sub-sampling unit) with reconstruction by spatial interpolation. The two reconstructed signals (RVH and RVL) at the coder are compared in a mode selector with the input video and a switch is set to transmit whichever of the compressed signals (SSH, SSL) gives the best match. A mode signal is also transmitted and, at the receiver decoder this operates a switch to select (RVH') or (RVL') correspondingly for feeding to the display. In a modified embodiment the sub-sampling unit does not employ a moving lattice but all samples for a four field sequence are taken from one field of each sequence.
Inventors
- 👤 Graham A. Thomas
- 👤 Timothy J. Borer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:15
CPC Classifications
H; H04; H04N; H04N11/00; H04N11/06; H04N11/12; H04N11/14; H04N11/16; H04N11/167; G; G06; G06T; G06T7/00; G06T7/20; G06T7/262; H04N11/02; H04N11/24; H04N11/28; H04N19/00; H04N19/42; H04N19/43; H04N19/50; H04N19/503; H04N19/51; H04N19/523; H04N19/527; H04N19/547; H04N19/59; H04N19/80; H04N5/00; H04N5/14; H04N5/144; H04N5/145; H04N7/00; H04N7/015; H04N7/0152; H04N7/0155; H04N7/0157; H04N7/12; H04N7/122; H04N7/125; H04N9/00; H04N9/64; H04N9/646
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
90 words
Receiving or playback apparatus for a reduced bandwidth video signal accompanied by a digital signal carrying motion vector information pertaining individually to a plurality of blocks of pixels, characterized by means for accumulating sub-sample points from the fields of each of a repeating cycle of fields, and means responsive to the motion vector information to shift the sub-sample points in accordance with the corresponding motion vector information so that the accumulated points provide a high-definition picture both in stationary areas and moving areas which are correlated from field to field.
Claim 2
Dependent Claim
90 words
Receiving or playback apparatus for a reduced bandwidth video signal accompanied by a digital signal carrying motion vector information pertaining individually to a plurality of blocks of pixels, characterized by means for accumulating sub-sample points from the fields of each of a repeating cycle of fields, and means responsive to the motion vector information to shift the sub-sample points in accordance with the corresponding motion vector information so that the accumulated points provide a high-definition picture both in stationary areas and moving areas which are correlated from field to field.
Claim 3
Dependent Claim
16 words
Apparatus according to claim 1, characterised by means for interpolating intermediate points among the accumulated points.
Claim 4
Dependent Claim
26 words
Apparatus according to claim 1, wherein the accumulated points of each field are derived from both preceding and succeeding fields of the same cycle of fields.
Claim 5
Dependent Claim
21 words
Apparatus according to claim 1, wherein the accumulated points of each field are derived only from that field and preceding fields.
Claim 6
Dependent Claim
54 words
Apparatus according to claim 1, further comprising means for reconstructing a picture by spatial interpolation of the sub-sample points received in one field only and means responsive to a mode signal accompanying the video signal to select for output between the picture reconstructed by accumulation of points and the picture reconstructed by spatial interpolation.
Claim 7
Dependent Claim
21 words
Apparatus according to claim 5, wherein the selecting means switch abruptly at the junction between two blocks sent in different modes.
Claim 8
Dependent Claim
21 words
Apparatus according to claim 5, wherein the selecting means switch gradually at the junction between two blocks sent in different modes.
Claim 9
Dependent Claim
44 words
Apparatus according to claim 1, comprising a framestore in which the high-definition picture is reconstructed and means for filing the framestore with an image generated by simple interpolation from the sub-sample points of a single field, before reconstruction by accumulation of points take place.
Claim 10
Dependent Claim
55 words
Apparatus according to claim 1, characterized by means for tracking motion vectors back from the field being reconstructed and for causing sub-sample points not to be included in the accumulation thereof when they pertain to a preceding or succeeding field and to a motion vector not reached by the tracking from the field being reconstructed.
Claim 11
Dependent Claim
17 words
Apparatus according to claim 1, comprising a following motion compensated standards converter responsive to the motion vectors.
Claim 12
Dependent Claim
100 words
Apparatus for producing a reduced bandwidth video signal from an input video signal, characterized by means for generating motion vectors describing the movement of each of a plurality of blocks of pixels making up a picture, means for sub-sampling the input video signals to provide in each field of each of a repeating cycle of fields a corresponding sub-set of picture points in correct spatial relationship to the points of the other fields of the same cycle, and means providing a composite signal comprising the video signal created by the sub-sampling means and a digital signal conveying the motion vectors.
Claim 13
Dependent Claim
100 words
Apparatus for producing a reduced bandwidth video signal from an input video signal, characterized by means for generating motion vectors describing the movement of each of a plurality of blocks of pixels making up a picture, means for sub-sampling the input video signals to provide in each field of each of a repeating cycle of fields a corresponding sub-set of picture points in correct spatial relationship to the points of the other fields of the same cycle, and means providing a composite signal comprising the video signal created by the sub-sampling means and a digital signal conveying the motion vectors.
Claim 14
Dependent Claim
25 words
Apparatus according to claim 11, wherein the sub-sampling means take all sub-sets of picture points for one cycle from the first field of that cycle.
Claim 15
Dependent Claim
36 words
Apparatus according to claim 11, wherein the sub-sampling means take each sub-set of picture points from the corresponding field, utilizing a sampling lattice displaced in accordance with the motion vectors describing the displacement of each block.
Claim 16
Dependent Claim
22 words
Apparatus according to claim 13, wherein the sampling lattice is restored to a datum position for the first field of each cycle.
Claim 17
Dependent Claim
46 words
Apparatus according to claim 11, comprising means for producing an alternative reduced bandwidth signal by field to field sub-sampling implementing spatial filtering, and means for selecting block by block between the two reduced bandwidth signals to utilize that signal which best matches the input video signal.
Claim 18
Dependent Claim
73 words
Apparatus according to claim 15, wherein the selecting means comprise means for reconstituting a high-definition signal from the first-mentioned reduced bandwidth signal, by accumulating subsample points from the fields of each cycle, shifted in accordance with the motion vectors, means for reconstituting a low-definition signal from the alternative reduced bandwidth signal by spatial interpolation and means for comparing each reconstituted signal with the input video signal to determine which provides the better match.
Claim 19
Dependent Claim
16 words
Apparatus according to claim 16, whereinthe comparing means performs a weighted comparison favouring the high-definition signal.
Claim 20
Dependent Claim
16 words
Apparatus according to claim 15, comprising a spatial pre-filter preceding the field to field sub-sampling means.
Claim 21
Dependent Claim
20 words
Apparatus according to claim 15, wherein the composite signal includes a mode signal indicating which reduced bandwidth signal is selected.
Claim 22
Dependent Claim
38 words
Apparatus according to claim 11, wherein the sub-sampling means are preceded by a vertical-temporal or temporal filter whose input samples are so displaced by the motion vectors that each moving block is filtered as if it were stationary.
Claim 23
Dependent Claim
18 words
Apparatus according to claim 11, wherein the sample structure is quincunxial and repeats over a four field cycle.
Claim 24
Dependent Claim
36 words
Apparatus according to claim 11, wherein the input video signal is an interlaced signal, the motion vectors are measured from picture to picture and these motion vectors are interpolated to provide field to field motion vectors.
Claim 25
Dependent Claim
55 words
Apparatus according to claim 11, wherein the means for generating motion vectors implement phase correlation between blocks of two successive images to extract dominant vectors as peaks in a correlation surface and each pixel or block of pixels is then assigned that one of the motion vectors which produces the match from image to image.
Claim 26
Dependent Claim
22 words
Apparatus according to claim 23, wherein the phase correlation is applied to large blocks and the vector assignment is to small blocks.
Claim 27
Dependent Claim
17 words
Apparatus according to claim 11, comprising a preliminary motion compensated standards converter responsive to the motion vectors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |