US5079547A
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Method of orthogonal transform coding/decoding
Assignee: Victor Company of Japan Ltd
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Filing: 1991-02-27
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Granted: 1992-01-07
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Expires: 2011-02-27
Abstract
Abstract There is provided the method of orthogonal transform coding/decoding to quantize/de-quantize transformed coefficients which are divided into a plurality of bands to which respective different numbers of coefficient are allotted. Quantization/de-quantization tables are arranged on the basis of a probability density function of the coefficient values designed on the assumption of a specified number of coefficients so as to correspond to the number of quantization/de-quantization bits. The values in the quantization/de-quantization tables selected according to the number of quantization/de-quantization bits are adaptively compensated on the basis of an actual number of coefficients on each band to quantize/de-quantize the coefficient values.
Inventors
- 👤 Norihiko Fuchigama
- 👤 Masaya Konishi
- 👤 Yasuhiro Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:59
CPC Classifications
G; G06; G06F; G06F17/00; G06F17/10; G06F17/14; H; H04; H04N; H04N19/00; H04N19/10; H04N19/102; H04N19/124; H04N19/126; H04N19/60
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
149 words
A method of orthogonal transform coding to quantize transformed coefficients which are divided into a plurality of bands to which respective different numbers of coefficients are allotted, comprising the steps of: arranging a plurality of quantization threshold level-tables designed on the basis of a probability density function of coefficient value on the assumption of a pre set number of coefficients, the quantization threshold level-tables corresponding to pre-set plural numbers of quantization bits respectively, selecting a table among the quantization threshold level-tables in response to a number of bits which the quantization of coefficients on a band is to be performed, and compensating the quantization levels in the selected table with the square root of a ratio of the number of coefficients on tee band to the pre-set number of coefficients, thus to compare the coefficient values and the compensated threshold levels with each other to quantize the coefficient values.
Claim 2
Independent Claim
149 words
A method of orthogonal transform coding to quantize transformed coefficients which are divided into a plurality of bands to which respective different numbers of coefficients are allotted, comprising the steps of: arranging a plurality of quantization threshold level-tables designed on the basis of a probability density function of coefficient value on the assumption of a pre set number of coefficients, the quantization threshold level-tables corresponding to pre-set plural numbers of quantization bits respectively, selecting a table among the quantization threshold level-tables in response to a number of bits which the quantization of coefficients on a band is to be performed, and compensating the quantization levels in the selected table with the square root of a ratio of the number of coefficients on tee band to the pre-set number of coefficients, thus to compare the coefficient values and the compensated threshold levels with each other to quantize the coefficient values.
Claim 3
Dependent Claim
42 words
The method according to claim 1, wherein the step of selecting the table is performed on the basis of calculating a signal-to-noise ratio defined by a ratio of the root-mean-square value of the coefficients on the band to a noise-masking threshold level.
Claim 4
Independent Claim
149 words
A method of orthogonal transform decoding to de-quantize quantized values of transformed coefficients which are divided into a plurality of bands to which respective different number of coefficients are allotted, comprising the steps of: arranging a plurality of de-quantized value-tables designed on the basis of a probability density function of coefficient value on the assumption of a pre-set number of coefficients, the de-quantized value-tables corresponding to pre-set plural numbers of de-quantization bits, and the steps being the same as each other, selecting a table among the de-quantized value-tables in response to a number of bits by which the quantization of coefficients on a band was performed, and compensating the de-quantized values in the selected table with the square root of a ratio of the number of coefficients on the band to the pre-set number of coefficients, the de-quantized values corresponding to the quantized values of coefficients on the band.
Claim 5
Independent Claim
149 words
A method of orthogonal transform decoding to de-quantize quantized values of transformed coefficients which are divided into a plurality of bands to which respective different number of coefficients are allotted, comprising the steps of: arranging a plurality of de-quantized value-tables designed on the basis of a probability density function of coefficient value on the assumption of a pre-set number of coefficients, the de-quantized value-tables corresponding to pre-set plural numbers of de-quantization bits, and the steps being the same as each other, selecting a table among the de-quantized value-tables in response to a number of bits by which the quantization of coefficients on a band was performed, and compensating the de-quantized values in the selected table with the square root of a ratio of the number of coefficients on the band to the pre-set number of coefficients, the de-quantized values corresponding to the quantized values of coefficients on the band.
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) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |