US5757975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Artifact reduction for large dynamic range input data in JPEG compression
Assignee: Xerox Corp
•
Filing: 1996-11-21
•
Granted: 1998-05-26
•
Expires: 2016-11-21
Abstract
Abstract A method of correcting out-of-range 8-bit pixel values, which should range from 0 to 255 by successively finding an out-of-range pixel, correcting it by adding (subtracting) an amount to restore that value to 0 (255), and then subtracting (adding) an equal amount to an adjacent pixel or pixels. An alternative, most useful for text, is to find an out-of-range pixel, and then replace it, and all adjacent pixels that are within a predetermined limit of 0 (255), with 0 (255).
Inventors
- 👤 Reiner Eschbach
- 👤 James E. Bollman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:42
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; G; G06; G06T; G06T9/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
67 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: receiving digital image data, finding an out-of-range pixel with a value less than 0, finding an adjacent pixel with a value greater than 0 but less than a predetermined limit, increasing the value of the out-of-range pixel, and decreasing the value of the adjacent pixel.
Claim 2
Independent Claim
67 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: receiving digital image data, finding an out-of-range pixel with a value less than 0, finding an adjacent pixel with a value greater than 0 but less than a predetermined limit, increasing the value of the out-of-range pixel, and decreasing the value of the adjacent pixel.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the value of the out-of-range pixel is increased to 0 and the adjacent pixel is reduced to 0.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the adjacent pixel is reduced by the absolute value of the out-of-range pixel and the value of the out-of-range pixel is then reduced to 0.
Claim 5
Independent Claim
67 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: receiving digital image data, finding an out-of-range pixel with a value more than 255, finding an adjacent pixel with a value less than 255 but more than a predetermined limit, decreasing the value of the out-of-range pixel, and increasing the value of the adjacent pixel.
Claim 6
Independent Claim
67 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: receiving digital image data, finding an out-of-range pixel with a value more than 255, finding an adjacent pixel with a value less than 255 but more than a predetermined limit, decreasing the value of the out-of-range pixel, and increasing the value of the adjacent pixel.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the value of the out-of-range pixel is decreased to 255 and the adjacent pixel is increased to 255.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein the value of the adjacent pixel is increased by the difference between the value of the out-of-range pixel and 255, and then the out-of-range pixel is reduced to 255.
Claim 9
Independent Claim
144 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: A. receiving digital image data, B. finding an out-of-range pixel, C. finding an adjacent pixel with a value greater than 0, if the out-of-range pixel has an absolute value smaller than that of an adjacent pixel, a. adding to the pixel a correction value which will bring the pixel value into range, and b. subtracting the correction value from the adjacent pixel, if the pixel has an absolute value larger than that of an adjacent pixel, c. increasing the out-of-range pixel by the value of the adjacent pixel, reducing the adjacent pixel value to 0, and returning to step C, and returning to step B if there are any remaining out-of-range pixels, otherwise, sending the image data to a raster output scanner.
Claim 10
Independent Claim
144 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: A. receiving digital image data, B. finding an out-of-range pixel, C. finding an adjacent pixel with a value greater than 0, if the out-of-range pixel has an absolute value smaller than that of an adjacent pixel, a. adding to the pixel a correction value which will bring the pixel value into range, and b. subtracting the correction value from the adjacent pixel, if the pixel has an absolute value larger than that of an adjacent pixel, c. increasing the out-of-range pixel by the value of the adjacent pixel, reducing the adjacent pixel value to 0, and returning to step C, and returning to step B if there are any remaining out-of-range pixels, otherwise, sending the image data to a raster output scanner.
Claim 11
Dependent Claim
12 words
The method of claim 7 wherein said data handling procedure is compression.
Claim 12
Independent Claim
108 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: A. receiving digital image data having out-of-range pixel values, B. finding an out-of-range pixel having a value greater than x, where the range is from 0 to x, C. finding an adjacent pixel with a value smaller than x, D. adding 1 to the adjacent pixel and subracting 1 from the out-of-range pixel until either of them equals x, if there is still an out-of-range pixel having a value greater than x, returning to step B, otherwise, sending the image data to a raster output scanner.
Claim 13
Independent Claim
108 words
A method of reducing artifacts introduced by a data handling procedure into digital image data to be printed, comprising the steps of: A. receiving digital image data having out-of-range pixel values, B. finding an out-of-range pixel having a value greater than x, where the range is from 0 to x, C. finding an adjacent pixel with a value smaller than x, D. adding 1 to the adjacent pixel and subracting 1 from the out-of-range pixel until either of them equals x, if there is still an out-of-range pixel having a value greater than x, returning to step B, otherwise, sending the image data to a raster output scanner.
Claim 14
Dependent Claim
12 words
The method of claim 9 wherein said data handling procedure is compression.
References Cited (Backward Citations)
US5278667A
Cited
US5224178A
Cited
US5339368A
Cited
US5379122A
Cited
US5359676A
Cited
US5589950A
Cited
US5521718A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-25 | 2001-11-24 | 2002-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-25 | 2005-11-24 | 2006-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-25 | 2009-11-24 | 2010-05-26 | $7700.00 | Window Closed / Lapsed |