Patent US5742708A successfully refreshed from Google Patents.
US5742708A
Expired / Lapsed
US
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Method and system for performing perspective projection conversion
Assignee: Xerox Corp
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Filing: 1995-11-15
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Granted: 1998-04-21
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Expires: 2015-11-15
Abstract
Abstract A system and process prints a high resolution image on a high addressable image output terminal by converting an image at one resolution to an image having a lower resolution in a fast-scan direction and a higher resolution in a pixel depth direction. The converted image is then processed and binarized prior to being printed on a high addressable printer. The system or process utilizes a conversion circuit which includes a two-bit per pixel packing circuit, a scanline buffer circuit, a logic circuit, and a look-up table. The conversion circuit initially converts the image into an image having a lower resolution in the fast-scan direction and a higher pixel depth resolution. Thereafter, the image is further converted to an image having a lower resolution in the slow-scan direction and a higher pixel depth resolution. This conversion of a high resolution image to a lower resolution is carried without any substantial lost to the image content data.
Inventors
- 👤 Thomas I. Yeh
- 👤 Francis K. Tse
- 👤 George W. Lahue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:16
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40075
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
179 words
A method for converting a high resolution binary image to a gray scale low resolution image, comprising the steps of: (a) receiving a first image having a first fast-scan resolution and a first pixel depth resolution; and (b) converting the first image having a first fast-scan resolution and a first pixel depth resolution to a second image having a second fast-scan resolution and a second pixel depth resolution, the second fast-scan resolution being lower than the first fast-scan resolution and the first pixel depth resolution being lower than the second pixel depth resolution; said step (b) including the substeps of, (b1) counting a number of ON pixels in a predetermined number of adjacent fast-scan pixels of the first image, (b2) generating a pixel having a pixel depth resolution of two and a value corresponding to the number of ON pixels counted in said substep (b1), (b3) summing a predetermined number of pixels generated in said substep (b2) which are adjacent in a slow-scan direction, and (b4) using the sum to index a look-up table which contains grayscale pixel values.
Claim 2
Independent Claim
179 words
A method for converting a high resolution binary image to a gray scale low resolution image, comprising the steps of: (a) receiving a first image having a first fast-scan resolution and a first pixel depth resolution; and (b) converting the first image having a first fast-scan resolution and a first pixel depth resolution to a second image having a second fast-scan resolution and a second pixel depth resolution, the second fast-scan resolution being lower than the first fast-scan resolution and the first pixel depth resolution being lower than the second pixel depth resolution; said step (b) including the substeps of, (b1) counting a number of ON pixels in a predetermined number of adjacent fast-scan pixels of the first image, (b2) generating a pixel having a pixel depth resolution of two and a value corresponding to the number of ON pixels counted in said substep (b1), (b3) summing a predetermined number of pixels generated in said substep (b2) which are adjacent in a slow-scan direction, and (b4) using the sum to index a look-up table which contains grayscale pixel values.
Claim 3
Independent Claim
157 words
A method for converting a high resolution binary image to a gray scale low resolution image, comprising the step of: (a) receiving a first image having a first fast-scan resolution and a first pixel depth resolution; and (b) converting the first image having a first fast-scan resolution and a first pixel depth resolution to a second image having a second fast-scan resolution and a second pixel depth resolution, the second fast-scan resolution being lower than the first fast-scan resolution and the trust pixel depth resolution being lower than the second pixel depth resolution; said step (b) including the substeps of, (1) generating a pixel having a pixel depth resolution of two from a predetermined number of adjacent fast-scan pixels of the first image, (b2) summing a predetermined number of pixels generated in said substep (b1) which are adjacent in a slow-scan direction, and (b3) using the sum to index a look-up table which contains grayscale pixel values.
Claim 4
Independent Claim
157 words
A method for converting a high resolution binary image to a gray scale low resolution image, comprising the step of: (a) receiving a first image having a first fast-scan resolution and a first pixel depth resolution; and (b) converting the first image having a first fast-scan resolution and a first pixel depth resolution to a second image having a second fast-scan resolution and a second pixel depth resolution, the second fast-scan resolution being lower than the first fast-scan resolution and the trust pixel depth resolution being lower than the second pixel depth resolution; said step (b) including the substeps of, (1) generating a pixel having a pixel depth resolution of two from a predetermined number of adjacent fast-scan pixels of the first image, (b2) summing a predetermined number of pixels generated in said substep (b1) which are adjacent in a slow-scan direction, and (b3) using the sum to index a look-up table which contains grayscale pixel values.
Claim 5
Independent Claim
183 words
A method for converting a high resolution binary image to a gray scale low resolution image, comprising the step of: (a) receiving a first image having a first fast-scan resolution and a first pixel depth resolution; and (b) converting the first image having a first fast-scan resolution and a fast pixel depth resolution to a second image having a second fast-scan resolution and a second pixel depth resolution, the second fast-scan resolution being lower than the first fast-scan resolution and the fast pixel depth resolution being lower than the second pixel depth resolution; said step (b) including the substeps of, (b1) generating a pixel having a pixel depth resolution of two from a predetermined number of adjacent fast-scan pixels of the first image, and (b2) using values of a predetermined number of the generated pixels adjacent in both a fast-scan and slow-scan direction to index a look-up table which contains pixel values corresponding to a fast-scan resolution being lower than the fast-scan resolution of the first image and a pixel depth resolution being higher than the pixel depth resolution of the first image.
Claim 6
Independent Claim
183 words
A method for converting a high resolution binary image to a gray scale low resolution image, comprising the step of: (a) receiving a first image having a first fast-scan resolution and a first pixel depth resolution; and (b) converting the first image having a first fast-scan resolution and a fast pixel depth resolution to a second image having a second fast-scan resolution and a second pixel depth resolution, the second fast-scan resolution being lower than the first fast-scan resolution and the fast pixel depth resolution being lower than the second pixel depth resolution; said step (b) including the substeps of, (b1) generating a pixel having a pixel depth resolution of two from a predetermined number of adjacent fast-scan pixels of the first image, and (b2) using values of a predetermined number of the generated pixels adjacent in both a fast-scan and slow-scan direction to index a look-up table which contains pixel values corresponding to a fast-scan resolution being lower than the fast-scan resolution of the first image and a pixel depth resolution being higher than the pixel depth resolution of the first image.
Claim 7
Dependent Claim
26 words
The method as claimed in claim 2, wherein the predetermined number of adjacent fast-scan pixels is three and the predetermined number of generated pixels in three.
Claim 8
Dependent Claim
26 words
The method as claimed in claim 2 wherein the predetermined number of adjacent fast-scan pixels is two and the predetermined number of generated pixels is two.
Claim 9
Dependent Claim
51 words
The method as claimed in claim 2, wherein said substep (a1) generates two pixels having a pixel depth resolution of two from three fast-scan pixels of the first image and said substep (a2) produces two sums by summing two out of three generated pixels which are adjacent in a slow-scan direction.
Claim 10
Dependent Claim
26 words
The method as claimed in claim 3 wherein the predetermined number of adjacent fast-scan pixels is two and the predetermined number of generated pixels is two.
Claim 11
Dependent Claim
54 words
The method as claimed in claim 3, wherein said substep (a1) generates two pixels having a pixel depth resolution of two from three fast-scan pixels of the first image and said substep (a2) uses values of two out of three generated pixels which are adjacent in a slow-scan direction to index the look-up table.
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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) | 2001-04-20 | 2001-10-20 | 2002-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-20 | 2005-10-20 | 2006-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-20 | 2009-10-20 | 2010-04-21 | $7700.00 | Window Closed / Lapsed |