US4258393A
Expired / Lapsed
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Picture processing method
Assignee: Ricoh Co Ltd
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Filing: 1979-11-01
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Granted: 1981-03-24
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Expires: 1999-11-01
Abstract
Abstract In a picture processing method according to the present invention, a picture element S(i,j) to be processed is divided into four smaller picture elements S 1 (i,j) through S 4 (i,j). The density of each of the smaller picture elements is determined from the algebraic mean value of the densities of the picture element and the picture elements surrounding the firstly mentioned picture elements. Each smaller picture element S m (i,j) (m=1,2,3, and 4) is determined by a DITHER MATRIX T(k,l) as S m (i,j)=1 when S m (i,j)≧T(k,l) and S m (i,j)=0 when S m (i,j)<T(k,l) where, using Gauss' notation, k=i-4[(i-1)/4] and l=j-4[(j-1)]/4].
Inventors
- 👤 Kouichi Ejiri
- 👤 Keiji Sekigawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:23
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/66; H04N5/70; H04N1/00; H04N1/40; H04N1/40068; H04N1/405; H04N1/4051
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
109 words
A picture element processing method, in which a picture element S(i,j) to be processed is divided into four smaller picture elements S 1 (i,j) through S 4 (i,j), the density of each of said smaller picture elements S 1 (i,j) through S 4 (i,j) is determined from the algebraic mean value of the densities of said picture element S(i,j) and picture elements surrounding said picture element, and each smaller picture element S m (i,j) (m=1, 2, 3 and 4) is determined by a DITHER MATRIX T(k,l) as S m (i,j)=1 when S m (i,j)≧T(k,l) and S m (i,j)=0 when S m (i,j)<T(k,l) where, using Gauss' notation, k=i-4[(i-1)/4] and l=j-4[(j-1)/4].
Claim 2
Dependent Claim
109 words
A picture element processing method, in which a picture element S(i,j) to be processed is divided into four smaller picture elements S 1 (i,j) through S 4 (i,j), the density of each of said smaller picture elements S 1 (i,j) through S 4 (i,j) is determined from the algebraic mean value of the densities of said picture element S(i,j) and picture elements surrounding said picture element, and each smaller picture element S m (i,j) (m=1, 2, 3 and 4) is determined by a DITHER MATRIX T(k,l) as S m (i,j)=1 when S m (i,j)≧T(k,l) and S m (i,j)=0 when S m (i,j)<T(k,l) where, using Gauss' notation, k=i-4[(i-1)/4] and l=j-4[(j-1)/4].
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) | 1984-03-23 | 1984-09-22 | 1985-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-23 | 1988-09-22 | 1989-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-23 | 1992-09-22 | 1993-03-24 | $7700.00 | Window Closed / Lapsed |