Patent US4965830A successfully refreshed from Google Patents.
US4965830A
Expired / Lapsed
US
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Apparatus for estimating distortion resulting from compressing digital data
Assignee: Unisys Corp
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Filing: 1989-01-17
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Granted: 1990-10-23
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Expires: 2009-01-17
Abstract
Abstract Apparatus for analyzing distortion levels of samples which occur in data compression systems of the type that may be integrated into a data compression system or used as a stand alone analyzer. The apparatus includes a processor that is coupled to the data compression system to provide the distortion analyzing apparatus with necessary input bit allocation and power level data for each sample. Memory storage is coupled to the processor for supplying predetermined unique quantization error values corresponding to each transform coefficient representing samples of digital data in a frame of digital data to be compressed. The program in the processor calculates the estimated distortion value for each of the transform coefficients by multiplying power level values stored in the storage times the predetermined unique quantization corresponding to each transformed coefficient to provide estimated distortion values which may be summed over a frame of digital data to provide an average distortion level for a frame of digital data.
Inventors
- 👤 Steven T. Barham
- 👤 Michael J. Hurst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:50
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/66; G; G06; G06T; G06T9/00; G06T9/005; H04B14/00; H04B14/02; H04B14/04; H04B14/046
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
164 words
Apparatus for calculating distortion levels resulting from compressing frames of digital data in a data compression system of the type having a transform device for generating transform coefficients X(k) of digital bit samples corresponding to a frame of digital data, said apparatus comprising: processing means, coupling means for coupling said processing means to said data compression system to provide bit data B, bit allocation data b(k) and power level data H 2 (k) for each transformed coefficient X(k), storage means coupled to said processing means for supplying predetermined unique quantization error values M(k) for each transformed coefficient X(k), said processor means having program means for calculating estimated distortion values D(k) for each transform coefficient X(k) where D(k) is equal to said power level data H 2 (k) times said quantization error value M(k), and means for summing a plurality of individual estimated distortion values D(k) to provide an average distortion level value DL for a frame of digital data being compressed using B bits.
Claim 2
Dependent Claim
164 words
Apparatus for calculating distortion levels resulting from compressing frames of digital data in a data compression system of the type having a transform device for generating transform coefficients X(k) of digital bit samples corresponding to a frame of digital data, said apparatus comprising: processing means, coupling means for coupling said processing means to said data compression system to provide bit data B, bit allocation data b(k) and power level data H 2 (k) for each transformed coefficient X(k), storage means coupled to said processing means for supplying predetermined unique quantization error values M(k) for each transformed coefficient X(k), said processor means having program means for calculating estimated distortion values D(k) for each transform coefficient X(k) where D(k) is equal to said power level data H 2 (k) times said quantization error value M(k), and means for summing a plurality of individual estimated distortion values D(k) to provide an average distortion level value DL for a frame of digital data being compressed using B bits.
Claim 3
Dependent Claim
25 words
Apparatus as set forth in claim 1 which further includes means for storing a plurality of distortion values DL and for producing distortion curve data.
Claim 4
Dependent Claim
31 words
Apparatus as set forth in claim 2 which further includes means for producing a curve of distortion values DL versus total bits allocated B for encoding a frame of digital data.
Claim 5
Dependent Claim
31 words
Apparatus as set forth in claim 2 which further includes programming means for determining the number of total bits B x required to achieve a predetermined distortion level DL x .
Claim 6
Dependent Claim
43 words
Apparatus as set forth in claim 1 which further includes means for supplying a new total bit value B n to said processing means, and program means for calculating a distortion level DL x for said new total bit value B n .
Claim 7
Dependent Claim
22 words
Apparatus as set forth in claim 5 wherein said means for supplying a new total bit value B n comprises keyboard means.
Claim 8
Dependent Claim
21 words
Apparatus as set forth in claim 6 which further includes visual output means for displaying said bit values B n .
Claim 9
Dependent Claim
35 words
Apparatus as set forth in claim 1 which further includes means for storing and displaying estimated distortion values D(k) for each transform coefficient X(k) and for analyzing the distortion of said data compression transform device.
Claim 10
Independent Claim
103 words
A method of estimating the number of bits required to maintain a predetermined average distortion level DL x comprising the steps of: transforming samples of digital data to provide transformed coefficient values X(k), calculating the number of bits B(k) to be allocated to each coefficient X(k) in order to achieve a predetermined total number of bits B x , determining an average power level H 2 (k) and quantization values M(k) for each coefficient X(k), calculating a distortion level D(k) for each coefficient value X(k), and analyzing said distortion level D(k) information to optimize the allocation of bits B x to be allocated.
Claim 11
Independent Claim
103 words
A method of estimating the number of bits required to maintain a predetermined average distortion level DL x comprising the steps of: transforming samples of digital data to provide transformed coefficient values X(k), calculating the number of bits B(k) to be allocated to each coefficient X(k) in order to achieve a predetermined total number of bits B x , determining an average power level H 2 (k) and quantization values M(k) for each coefficient X(k), calculating a distortion level D(k) for each coefficient value X(k), and analyzing said distortion level D(k) information to optimize the allocation of bits B x to be allocated.
Claim 12
Dependent Claim
29 words
A method as set forth in claim 9 which further includes the steps of: computing an average distortion level DL by summing and normalizing said individual distortion levels (D(k).
Claim 13
Dependent Claim
46 words
A method as set forth in claim 10 which further includes steps of: comparing said average distortion level DL with a predetermined desired distortion level DL x , and selecting a new number of bits B x to achieve said desired distortion level DL x .
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) | 1993-10-22 | 1994-04-23 | 1994-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-22 | 1998-04-23 | 1998-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-22 | 2002-04-23 | 2002-10-23 | $7700.00 | Window Closed / Lapsed |