US5220647A
Expired / Lapsed
US
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Image processing method
Assignee: Sharp Corp
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Filing: 1988-12-08
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Granted: 1993-06-15
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Expires: 2008-12-08
Abstract
Abstract A method for processing images is useful for generating a chain code representation of a configuration of pixels in an image. The method stores a pixel representation in first frame memory. For each pixel, "convolution information" is stored in a second frame memory. Convolution information indicates whether neighborhood pixels are part of the configuration. In one embodiment, convolution information for an object pixel is a bit string. The location of a bit in the string corresponds to a direction of displacement from the object pixel. The value of a bit in the string indicates whether a neighborhood pixel located in the corresponding direction is part of the configuration. A first method for generating a chain code expression examines the convolution information for a bit which identifies an adjacent configuration pixel. Examination begins from a bit location determined from a prior code in the chain. The position of the identified bit is then the next code in the chain. An alternate method uses a look-up table. The address of the look-up tab is the convolution information expression, and the content of the table is a chain code.
Inventors
- 👤 Ryohei Kumagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:55
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
112 words
A method for generating a chain code representation of a configuration of pixels in an image comprising steps of: generating a pixel representation of the image; generating first neighborhood-information expression for an object pixel of the configuration, said neighborhood-information expression representing coincidence of density between the object pixel and pixels in a neighborhood around the object pixel; generating a neighborhood-information expression for each of a plurality of pixels of the configuration; storing said neighborhood-information expressions in a frame memory; obtaining a chain code representing the object pixel from the first neighborhood-information expression; and representing the configuration as a sequence of chain codes including a chain code obtained from the first neighborhood-information expression.
Claim 2
Independent Claim
112 words
A method for generating a chain code representation of a configuration of pixels in an image comprising steps of: generating a pixel representation of the image; generating first neighborhood-information expression for an object pixel of the configuration, said neighborhood-information expression representing coincidence of density between the object pixel and pixels in a neighborhood around the object pixel; generating a neighborhood-information expression for each of a plurality of pixels of the configuration; storing said neighborhood-information expressions in a frame memory; obtaining a chain code representing the object pixel from the first neighborhood-information expression; and representing the configuration as a sequence of chain codes including a chain code obtained from the first neighborhood-information expression.
Claim 3
Dependent Claim
26 words
An image processing method as in claim 1 wherein said convolution-information expression comprises four bits indicating density differences between said object pixel and four adjacent pixels.
Claim 4
Dependent Claim
26 words
An image processing method as in claim 1 wherein said convolution-information expression comprises eight bits indicating density differences between said object pixel and eight adjacent pixels.
Claim 5
Dependent Claim
33 words
An image processing method as in claim 1, wherein said convolution information comprises an ordered string of convolution-information bits, said convolution-information bits indicating density differences between said object pixel and 8 adjacent pixels.
Claim 6
Dependent Claim
37 words
An image processing method as in claims 1 wherein said pixels in an image convolution information is stored in a first frame memory, and pixel values of said object pixels are stored in a second frame memory.
Claim 7
Dependent Claim
68 words
A method as in claim 1 wherein the step of generating a first convolution-information expression includes a step of generating a first ordered string of bits, a location of a bit in the ordered string corresponding to a direction in the image, a value of a bit in the string indicating that a pixel adjacent to the object pixel in the corresponding direction is part of the configuration.
Claim 8
Dependent Claim
57 words
A method as in claim 6 wherein the step of obtaining a chain code representing the object pixel from the first convolution-information expression includes a step of examining bits in the first ordered string beginning from a first position in the order, said first position determined from a chain code of a prior pixel in the configuration.
Claim 9
Dependent Claim
52 words
A method as in claim 6 wherein the step of obtaining a chain code representing the object pixel from the first convolution-information expression includes steps of: storing the first ordered string in register; shifting the string a plurality of times; and testing a first bit position in the string after each shift.
Claim 10
Dependent Claim
48 words
A method as in claim 6 wherein the step of obtaining a chain code representing the object pixel from the first convolution-information expression includes steps of: generating and storing a look-up table, said table addressed by the convolution-information expression, the contents of said look-up table comprising chain codes.
Claim 11
Dependent Claim
162 words
A method as in claim 6 wherein the step of generating a first ordered string of bits includes steps of: storing a first line of pixels in a first line memory; storing a second line of pixels in a second line memory; storing a first pixel of a third line of pixels in a first storage cell and storing a second pixel of the third line of pixels in a second storage cell; storing a first pixel of the second line of pixels in a third storage cell and storing a second pixel of the second line of pixels in a fourth storage cell; storing a first pixel of the first line of pixels in a fifth storage cell and storing a second pixel of the first line of pixels in a sixth storage cell; and logically combining first, second and third pixels from each of the first, second and third lines of pixels thereby generating the first ordered string of bits.
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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) | 1996-06-14 | 1996-12-14 | 1997-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-14 | 2000-12-14 | 2001-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-14 | 2004-12-14 | 2005-06-15 | $7700.00 | Window Closed / Lapsed |