US4918524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
HDTV Sub-band coding using IIR filter bank
Assignee: Iconectiv LLC
•
Filing: 1989-03-14
•
Granted: 1990-04-17
•
Expires: 2009-03-14
Abstract
Abstract A technique for the sub-band decomposition and reconstruction of video signals is disclosed. In an illustrative embodiment of the present invention, each field of a video signal is decomposed into sub-bands utilizing a polyphase filter bank unit including an infinite impulse response allpass filter with coefficients that are powers of two. To reconstruct the original image, an FIR is utilized which approximates an IIR allpass filter This eliminates the need for a full field memory in the reconstruction process.
Inventors
- 👤 Rashid Ansari
- 👤 Antonio Fernandez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:51
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/60; H04N19/63; H03; H03H; H03H17/00; H03H17/02; H03H17/0248; H03H17/0264; H03H17/0266; H04N7/00; H04N7/015; H04N19/10; H04N19/102; H04N19/13
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
80 words
A method for coding a video signal comprising the steps of dividing said video signal into a plurality of sub-band signals by applying said signal to at least one polyphase filter bank unit comprising two signal processing paths one of which paths includes an infinite impulse response allpass filter, and reconstructing said video signal by applying said sub-band signal to at least one filter bank unit comprising two signal processing paths one of which includes a finite impulse response filter.
Claim 2
Independent Claim
80 words
A method for coding a video signal comprising the steps of dividing said video signal into a plurality of sub-band signals by applying said signal to at least one polyphase filter bank unit comprising two signal processing paths one of which paths includes an infinite impulse response allpass filter, and reconstructing said video signal by applying said sub-band signal to at least one filter bank unit comprising two signal processing paths one of which includes a finite impulse response filter.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein at least one of said sub-band signals is coded using a discrete cosine transform.
Claim 4
Dependent Claim
39 words
The method of claim 1 wherein each coefficient of said allpass filter is a power of two, and each coefficient of said finite impulse response filter is a power of two or a sum of two powers of two.
Claim 5
Independent Claim
125 words
A device for coding a video signal comprising a sequence of samples, said device comprising: at least one filter bank unit for receiving said video signal and for analyzing said video signal into a plurality of sub-band signals, said filter bank unit being a polyphase filter bank unit including means for separating said sequence of samples into two sequences of samples at half the rate of said original sequence on two separate paths, means for synchronizing said two sequences of samples, an allpass infinite impulse response filter located in one of said paths, and means for obtaining the sum and difference of said two sequences of samples to obtain said sub-band signals, said device further comprising means for coding each of said sub-band signals individually.
Claim 6
Independent Claim
125 words
A device for coding a video signal comprising a sequence of samples, said device comprising: at least one filter bank unit for receiving said video signal and for analyzing said video signal into a plurality of sub-band signals, said filter bank unit being a polyphase filter bank unit including means for separating said sequence of samples into two sequences of samples at half the rate of said original sequence on two separate paths, means for synchronizing said two sequences of samples, an allpass infinite impulse response filter located in one of said paths, and means for obtaining the sum and difference of said two sequences of samples to obtain said sub-band signals, said device further comprising means for coding each of said sub-band signals individually.
Claim 7
Dependent Claim
21 words
The device of claim 4 wherein said allpass infinite impulse response filter includes only filter coefficients which are powers of two.
Claim 8
Dependent Claim
68 words
The device of claim 4 wherein said device includes further filter bank units for further analyzing said sub-band signals, each of said further filter bank units being a polyphase filter bank unit including means for separating an input sequence of samples into two sequence samples at half the rate of the input sequence on two separate paths, one of said paths including an infinite impulse response allpass filter.
Claim 9
Dependent Claim
99 words
A sub-band coding system for a video signal comprising a first set of filter bank units for dividing said video signal into a plurality of sub-band signals, each of said filter bank units in said first set being a polyphase filter bank unit comprising two signal processing paths, one of which includes an infinite impulse response allpass filter, and a second set of filter bank units for synthesizing said video signal from said sub-band signals, each of said filter bank units in said second set comprising two signal processing paths, one of which includes a finite impulse response filter.
Claim 10
Dependent Claim
99 words
A sub-band coding system for a video signal comprising a first set of filter bank units for dividing said video signal into a plurality of sub-band signals, each of said filter bank units in said first set being a polyphase filter bank unit comprising two signal processing paths, one of which includes an infinite impulse response allpass filter, and a second set of filter bank units for synthesizing said video signal from said sub-band signals, each of said filter bank units in said second set comprising two signal processing paths, one of which includes a finite impulse response filter.
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) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |