US5041920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image halftone generation by static RAM look-up table
Assignee: Xerox Corp
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Filing: 1989-11-15
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Granted: 1991-08-20
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Expires: 2009-11-15
Abstract
Abstract A halftone conversion system for converting digital pixels to binary pixels in which individual matrices in a memory having progressively changing x, y matrices of binary pixels are addressed by an address composed of a block of x pixels including the pixel being processed, a block of y lines including the line containing the pixel being processed, and the digital value of the pixel being processed, the pixel located at the x, y coordinates of the addressed matrix providing the binary pixel output.
Inventors
- 👤 Thomas A. Hayes
- 👤 James W. Stevens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:53
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4051
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
148 words
A method for converting lines L of input pixels P representing an image in digital form to output pixels in binary form, comprising the steps of: a) storing a succession of progressively changing binary pixel matrices x pixels wide and y lines long in memory; b) for each input pixel P in each line L, providing a memory address composed of a block of x pixels including a representation of said pixel P, a block of y lines including the line L in which said representation of said pixel P resides, and a digital value of said pixel P; c) addressing said memory with the address from step b to access a pixel matrix corresponding to said address; and d) from the pixel matrix obtained in step c, selecting a predetermined one of the pixels in said matrix as a binary output pixel representative of said pixel P.
Claim 2
Independent Claim
148 words
A method for converting lines L of input pixels P representing an image in digital form to output pixels in binary form, comprising the steps of: a) storing a succession of progressively changing binary pixel matrices x pixels wide and y lines long in memory; b) for each input pixel P in each line L, providing a memory address composed of a block of x pixels including a representation of said pixel P, a block of y lines including the line L in which said representation of said pixel P resides, and a digital value of said pixel P; c) addressing said memory with the address from step b to access a pixel matrix corresponding to said address; and d) from the pixel matrix obtained in step c, selecting a predetermined one of the pixels in said matrix as a binary output pixel representative of said pixel P.
Claim 3
Independent Claim
135 words
A method for halftone processing multi-bit input pixels to provide a binary output pixel for each of said input pixels, comprising the steps of: a) storing discrete x, y halftone pixel matrices in a memory; b) for each input pixel, providing a composite address comprised of a block of x pixels including a said input pixel, a block of y image lines including the line containing said representation of said input pixel, and a digital image value of said input pixel; c) using said composite address, addressing a predetermined one of said x, y halftone pixel matrices in said memory; and d) from the x, y matrix addressed in step b, outputting a binary representation of a predetermined one of the pixels in said addressed matrix as said binary pixel output for said input pixel.
Claim 4
Independent Claim
135 words
A method for halftone processing multi-bit input pixels to provide a binary output pixel for each of said input pixels, comprising the steps of: a) storing discrete x, y halftone pixel matrices in a memory; b) for each input pixel, providing a composite address comprised of a block of x pixels including a said input pixel, a block of y image lines including the line containing said representation of said input pixel, and a digital image value of said input pixel; c) using said composite address, addressing a predetermined one of said x, y halftone pixel matrices in said memory; and d) from the x, y matrix addressed in step b, outputting a binary representation of a predetermined one of the pixels in said addressed matrix as said binary pixel output for said input pixel.
Claim 5
Dependent Claim
29 words
The method according to claim 2 including the step of: outputting binary representation of the pixel at the x, y coordinates of said matrix which define said input pixel.
Claim 6
Dependent Claim
26 words
The method according to claim 2 including the step of: indexing said block of x pixels by one for each succeeding into pixel to be processed.
Claim 7
Dependent Claim
31 words
The method according to claim 4 including the step of: indexing said block of y image line by one when processing of a last input pixel in the line is completed.
Claim 8
Dependent Claim
127 words
An image signal conversion process for converting input pixels from digital to binary, comprising the steps of: a) storing progressively changing halftone matrices of binary pixels in memory, each of said matrices comprising a matrix x pixels wide and y pixels long; b) for each of said digital pixels, providing a composite address for addressing a predetermined one of said matrices in said memory comprising a block x pixels wide, y lines long, and a digital value of said pixel; c) using said address, addressing said memory to obtain a halftone matrix corresponding to said address from said memory; and d) from the halftone matrix obtained in step c, selecting a binary pixel in said matrix corresponding in position to x, y coordinates of said input pixel.
Claim 9
Dependent Claim
127 words
An image signal conversion process for converting input pixels from digital to binary, comprising the steps of: a) storing progressively changing halftone matrices of binary pixels in memory, each of said matrices comprising a matrix x pixels wide and y pixels long; b) for each of said digital pixels, providing a composite address for addressing a predetermined one of said matrices in said memory comprising a block x pixels wide, y lines long, and a digital value of said pixel; c) using said address, addressing said memory to obtain a halftone matrix corresponding to said address from said memory; and d) from the halftone matrix obtained in step c, selecting a binary pixel in said matrix corresponding in position to x, y coordinates of said input pixel.
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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) | 1994-08-19 | 1995-02-18 | 1995-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-19 | 1999-02-18 | 1999-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-19 | 2003-02-18 | 2003-08-20 | $7700.00 | Window Closed / Lapsed |