US4794455A
Expired / Lapsed
US
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Method and apparatus employing adaptive filtering for efficiently communicating image sequences
Assignee: ACCEL CAPITAL (INTERNATIONAL) LP
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Filing: 1988-03-21
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Granted: 1988-12-27
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Expires: 2008-03-21
Abstract
Abstract A method and apparatus for encoding and transmitting a sequence of image frames employ a measure of motion displacement for generating a motion compensated image. The motion compensated image, together with an error signal, provides the receiver with full detail regarding the next frame of a sequence. In some instances, however, the motion displacement data is inaccurate for portions of the next image frame. In those instances, the method and apparatus determine whether filtering of a portion of the motion compensated image provides a lower error energy for the resulting prediction of the image. If a lower error energy can be achieved by low-pass filtering, the data regarding the additional processing of the motion compensated reconstructed image is transmitted to the receiver.
Inventors
- 👤 S. Staffan Ericsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:24
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/50; H04N19/503; H04N19/51; H04N19/577
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
146 words
A method for encoding and transmitting a sequence of image frames comprising the steps of estimating, for successive image of the sequence, and for each of a plurality of multi-pixel blocks of the image, a measure of motion displacement of each block between successive images, generating, using said measures of motion displacement, a motion compensated image, selecting, for each block of an image frame representation, one block chosen from between corresponding blocks of, respectively, said motion compensated image and a low-pass filter representation of said motion compensated image, and transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a motion compensated receiver image, said filter selection data being dependent upon the selecting step at the transmitter.
Claim 2
Independent Claim
146 words
A method for encoding and transmitting a sequence of image frames comprising the steps of estimating, for successive image of the sequence, and for each of a plurality of multi-pixel blocks of the image, a measure of motion displacement of each block between successive images, generating, using said measures of motion displacement, a motion compensated image, selecting, for each block of an image frame representation, one block chosen from between corresponding blocks of, respectively, said motion compensated image and a low-pass filter representation of said motion compensated image, and transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a motion compensated receiver image, said filter selection data being dependent upon the selecting step at the transmitter.
Claim 3
Dependent Claim
95 words
The method of claim 1 wherein said selecting step comprises the steps of generating a low-pass image representation of each block of the motion compensated image, determining a value of a motion compensated image error associated with each block of the motion compensated image, determining a value of a low-pass image error associated with each block of the generated low-pass image representation, and setting, in response to said motion compensated and low-pass image error values, for each block, a data bit identifying whether to subject the block of the motion compensated image to low-pass filtering.
Claim 4
Dependent Claim
27 words
The method of claim 2 wherein said representation generating step comprises the step of applying a block averaging filter process at each picture element of a block.
Claim 5
Dependent Claim
20 words
The method of claim 2 further comprising the step of compressing said data bits using a variable length coding procedure.
Claim 6
Dependent Claim
150 words
Apparatus for encoding and transmitting a sequence of image frames comprising means for estimating, for successive images of the sequence, and for each of a plurality of multi-pixel blocks of the image, a measure of motion displacement of each block between successive images, means for generating, using said measures of motion displacement, a motion compensated image, means for selecting for each block of an image frame representation, one block chosen from between corresponding blocks of, respectively, said motion compensated image and a low-pass filtered representation of said motion compensated image, and means for transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a motion compensated receiver image, said filter selection data being dependent upon the selecting means at the transmitter.
Claim 7
Dependent Claim
150 words
Apparatus for encoding and transmitting a sequence of image frames comprising means for estimating, for successive images of the sequence, and for each of a plurality of multi-pixel blocks of the image, a measure of motion displacement of each block between successive images, means for generating, using said measures of motion displacement, a motion compensated image, means for selecting for each block of an image frame representation, one block chosen from between corresponding blocks of, respectively, said motion compensated image and a low-pass filtered representation of said motion compensated image, and means for transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a motion compensated receiver image, said filter selection data being dependent upon the selecting means at the transmitter.
Claim 8
Dependent Claim
99 words
The apparatus of claim 5 wherein said selecting means comprises means for generating a low-pass filtered image representation of each block of the reconstructed motion image, means for determining a value of a reconstructed image error associated with each block of the reconstructed motion image, means for determining a value of a low-pass image error associated with each block of the generated low-pass image representation, and means for setting, in response to said reconstructed and low-pass image error values, for each block, a data bit identifying whether to subject the block of the reconstructed motion image to low-pass filtering.
Claim 9
Dependent Claim
29 words
The apparatus of claim 6 wherein said representation generating means comprises means for applying a block averaging filter process at each picture element of a block of the image.
Claim 10
Independent Claim
118 words
A method for encoding and transmitting a sequence of image frames comprising the steps of dividing the image into a plurality of block regions, generating a data coding of the high spatial frequency information content of said image, determining for each block region an error value for each of a filtered image prediction of the block represented by said data coding and of an image prediction using said data coding without filtering, and transmitting said data coding and a filter selection data over a communications channel to a receiver to enable said receiver to determine, for each block region of an image, whether to employ low-pass filtering in generating a receiver prediction image from a received data coding.
Claim 11
Independent Claim
118 words
A method for encoding and transmitting a sequence of image frames comprising the steps of dividing the image into a plurality of block regions, generating a data coding of the high spatial frequency information content of said image, determining for each block region an error value for each of a filtered image prediction of the block represented by said data coding and of an image prediction using said data coding without filtering, and transmitting said data coding and a filter selection data over a communications channel to a receiver to enable said receiver to determine, for each block region of an image, whether to employ low-pass filtering in generating a receiver prediction image from a received data coding.
Claim 12
Dependent Claim
53 words
The method of claim 8 further wherein said generating step comprises the steps of estimating, for successive images of the sequence, and for each block, a measure of motion displacement of each block from one image frame to a next image frame, and encoding, using a lossy compression device, said motion displacement measures.
Claim 13
Independent Claim
122 words
An apparatus for encoding and transmitting a sequence of image frames comprising means for dividing the image into a plurality of block regions, means for generating a data coding of the high spatial frequency information content of said image, means for determining for each block region an error value for each of a filtere image prediction of the block represented by said data coding and of an image prediction using said data coding without filtering, and means for transmitting said data coding and a filter selection data over a communications channel to a receiver to enable said receiver to determine, for each block region of the image, whether to employ low-pass filtering in generating a receiver image from a received data coding.
Claim 14
Independent Claim
122 words
An apparatus for encoding and transmitting a sequence of image frames comprising means for dividing the image into a plurality of block regions, means for generating a data coding of the high spatial frequency information content of said image, means for determining for each block region an error value for each of a filtere image prediction of the block represented by said data coding and of an image prediction using said data coding without filtering, and means for transmitting said data coding and a filter selection data over a communications channel to a receiver to enable said receiver to determine, for each block region of the image, whether to employ low-pass filtering in generating a receiver image from a received data coding.
Claim 15
Dependent Claim
54 words
The apparatus of claim 10 further wherein said generating means comprises means for estimating, for successive images of the sequence, and for each block, a measure of motion displacement of each block from one image frame to a next image frame, and means for encoding, using a lossy compression device, said motion displacement measures.
Claim 16
Independent Claim
112 words
A method for encoding and transmitting a sequence of image frames comprising the steps of selecting, for successive images of the sequence, and for each of a plurality of multi-pixel blocks of the image, one block chosen from between corresponding blocks of, respectively, a previous image and a low-pass filter representation of said previous image, and transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a previous receiver image, said filter selection data being dependent upon the selecting step at the transmitter.
Claim 17
Independent Claim
112 words
A method for encoding and transmitting a sequence of image frames comprising the steps of selecting, for successive images of the sequence, and for each of a plurality of multi-pixel blocks of the image, one block chosen from between corresponding blocks of, respectively, a previous image and a low-pass filter representation of said previous image, and transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a previous receiver image, said filter selection data being dependent upon the selecting step at the transmitter.
Claim 18
Dependent Claim
112 words
Apparatus for encoding and transmitting a sequence of image frames comprising means for selecting, for successive images of the sequence, and for each of a plurality of multi-pixel blocks of the image, one block chosen from between corresponding blocks of, respectively, a previous image and a low-pass filtered representation of said previous image, and means for transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a previous receiver image, said filter selection data being dependent upon the selecting means at the transmitter.
Claim 19
Dependent Claim
112 words
Apparatus for encoding and transmitting a sequence of image frames comprising means for selecting, for successive images of the sequence, and for each of a plurality of multi-pixel blocks of the image, one block chosen from between corresponding blocks of, respectively, a previous image and a low-pass filtered representation of said previous image, and means for transmitting filter selection data over a communications channel to enable a receiver to determine for a block of the image being transmitted whether to employ low-pass filtering in said block of the image in generating a prediction image from a previous receiver image, said filter selection data being dependent upon the selecting means at the transmitter.
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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) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |