US4759076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image rotating system by an arbitrary angle
Assignee: Mitsubishi Electric Corp
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Filing: 1986-02-25
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Granted: 1988-07-19
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Expires: 2006-02-25
Abstract
Abstract A system for rotating an image by an arbitrary angle which is effective in image processing techniques using terminal equipment such as a work station, and will not distort a rotated image even with an increasing rotation angle θ. Skew transformation is implemented for respective skew angles in horizontal and vertical directions corresponding to a desired rotation angle three times alternately, so that affine transformation for image rotation may be replaced by triple skew transformations. Thus, arbitrary two-dimensional image data is precisely rotated by any desired angle at high speeds without resorting to approximation of the arithmetic equation.
Inventors
- 👤 Atsushi Tanaka
- 👤 Masatoshi Kameyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:11
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/60; G06T3/608; H; H04; H04N; H04N1/00; H04N1/387; H04N1/3877; H04N1/3878
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
155 words
A system for rotating an image by an arbitrary angle, comprising: an image memory for storing two-dimensional image data; a transformation angle determining section for determining both a first skew angle in a first direction and a second skew angle in a second, different direction for original two-dimensional image data stored in said image memory, in accordance with a desired rotation angle; a first skew transformation section for obtaining second two-dimensional image data which is derived from skewing said original two-dimensional image data in said first direction by said first skew angle; a second skew transformation section for obtaining third two-dimensional image data which is derived from skewing said second two-dimensional image data in said second direction by said second skew angle; and a third skew transformation section for obtaining fourth two-dimensional image data which is derived from skewing said third two-dimensional image data in said first direction once again by said first skew angle.
Claim 2
Independent Claim
155 words
A system for rotating an image by an arbitrary angle, comprising: an image memory for storing two-dimensional image data; a transformation angle determining section for determining both a first skew angle in a first direction and a second skew angle in a second, different direction for original two-dimensional image data stored in said image memory, in accordance with a desired rotation angle; a first skew transformation section for obtaining second two-dimensional image data which is derived from skewing said original two-dimensional image data in said first direction by said first skew angle; a second skew transformation section for obtaining third two-dimensional image data which is derived from skewing said second two-dimensional image data in said second direction by said second skew angle; and a third skew transformation section for obtaining fourth two-dimensional image data which is derived from skewing said third two-dimensional image data in said first direction once again by said first skew angle.
Claim 3
Dependent Claim
31 words
An image rotating system according to claim 1, wherein said desired rotation angle is θ, said first skew angle is θ/2 and said second skew angle is tan -1 (sin θ).
Claim 4
Dependent Claim
24 words
An image rotating system according to claim 2, wherein said first direction is a horizontal direction and said second direction is a vertical direction.
Claim 5
Dependent Claim
24 words
An image rotating system according to claim 2, wherein said first direction is a vertical direction and said second direction is a horizontal direction.
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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) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |