US5867142A
Expired / Lapsed
US
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System and method for processing an image having edges
Assignee: Xerox Corp
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Filing: 1991-11-25
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Granted: 1999-02-02
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Expires: 2011-11-25
Abstract
Abstract A method of processing an image to reduce false granularity, or "aliasing", resulting from the reproduction of edges using fixed size pixels. In the preferred embodiment of the invention, certain pixels adjacent to black pixels corresponding to an edge are set to a gray level. The setting of certain pixels to a gray level involves detecting a pattern in a block of pixels by detecting subpatterns within the block of pixels.
Inventors
- 👤 Tracy E. Thieret
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:36
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/409; H04N1/4092; G; G09; G09G; G09G5/00; G09G5/20
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
167 words
A method of processing an input image having a plurality of input pixels to generate an output image having a plurality of output pixels, comprising the steps performed for each input pixel, of: a first forming step of forming a first value from intensities of a first set of pixels around the input pixel; determining whether the first value is a member of a first set of values; a first setting step of setting an output pixel intensity, corresponding to the input pixel, in accordance with an intensity of the input pixel, if the first value is not a member of the first set of values; otherwise, a second forming step of forming a second value from intensities of a second set of pixels around the input pixel, the second set of pixels including a pixel that is not included in the first set of pixels; a second setting step of setting an output pixel intensity, corresponding to the input pixel, in accordance with the second value.
Claim 2
Independent Claim
167 words
A method of processing an input image having a plurality of input pixels to generate an output image having a plurality of output pixels, comprising the steps performed for each input pixel, of: a first forming step of forming a first value from intensities of a first set of pixels around the input pixel; determining whether the first value is a member of a first set of values; a first setting step of setting an output pixel intensity, corresponding to the input pixel, in accordance with an intensity of the input pixel, if the first value is not a member of the first set of values; otherwise, a second forming step of forming a second value from intensities of a second set of pixels around the input pixel, the second set of pixels including a pixel that is not included in the first set of pixels; a second setting step of setting an output pixel intensity, corresponding to the input pixel, in accordance with the second value.
Claim 3
Dependent Claim
88 words
The method of claim 1, wherein the determining step includes the substeps of: reading a location in a first memory means using the first value; determining that the first value is a member of a first set of values, if the location contains a certain value, and wherein the second setting step includes the substeps of selecting a pattern, using the first value; and determining whether the second value substantially matches the pattern; setting the output pixel, in accordance with whether the second value substantially matches the pattern.
Claim 4
Dependent Claim
92 words
The method of claim 1, wherein the determining step includes the substeps of: reading a location in a first memory means using the first value; determining that the first value is a member of a first set of values, if the location contains a certain value, and wherein the second setting step includes the substeps of reading a plurality of locations in a second memory means using the first value, to produce a plurality of masks; and setting the output pixel, in accordance with the second value and the plurality of masks.
Claim 5
Dependent Claim
94 words
The method of claim 3, wherein the plurality of masks include first, second, and third masks each having a digit corresponding to each pixel in the second set of pixels, respectively, and the second setting step includes the substeps of comparing the second value to the first mask; comparing the second value to the second mask; comparing the second value to the third mask; and reading a location in a third memory means using the first value to produce an intensity value for the output pixel, depending on the results of the comparing steps.
Claim 6
Dependent Claim
119 words
The method of claim 3, wherein the plurality of masks include first, second, and third masks each having a digit corresponding to each pixel in the second set of pixels, respectively, and the second setting step includes the substeps of a first step of ANDing the second value with the first mask; a second step of ANDing the second value with the second mask; a third step of ANDing the second value to the third mask; reading a location in a third memory means using the first value to produce an intensity value for the output pixel, if the results of the first and second ANDing steps is nonzero and the result of the third ANDing step if zero.
Claim 7
Dependent Claim
36 words
The method of claim 1, wherein the second forming step includes the substep of forming the second value from intensities of a second set of pixels that are mutually exclusive from the first set of pixels.
Claim 8
Dependent Claim
34 words
The method of claim 1, wherein the second forming step includes the substep of forming the second value from intensities of a second set of pixels that are surrounding the first set of pixels.
Claim 9
Independent Claim
158 words
A system for processing an input image having a plurality of input pixels to generate an output image having a plurality of output pixels, comprising: a first forming step of forming a first value from intensities of a first set of pixels around the input pixel; means for determining whether the first value is a member of a first set of values; first setting means for setting a output pixel intensity, corresponding to the input pixel, in accordance with an intensity of the input pixel, if the first value is not a member of the first set of values; second forming means for forming a second value from intensities of a second set of pixels around the input pixel, the second set of pixels including a pixel that is not included in the first set of pixels; and second setting means for setting an output pixel intensity, corresponding to the input pixel, in accordance with the second value.
Claim 10
Independent Claim
158 words
A system for processing an input image having a plurality of input pixels to generate an output image having a plurality of output pixels, comprising: a first forming step of forming a first value from intensities of a first set of pixels around the input pixel; means for determining whether the first value is a member of a first set of values; first setting means for setting a output pixel intensity, corresponding to the input pixel, in accordance with an intensity of the input pixel, if the first value is not a member of the first set of values; second forming means for forming a second value from intensities of a second set of pixels around the input pixel, the second set of pixels including a pixel that is not included in the first set of pixels; and second setting means for setting an output pixel intensity, corresponding to the input pixel, in accordance with the second value.
Claim 11
Dependent Claim
98 words
The system of claim 8, wherein the determining means includes a first memory means; means for reading a location in the first memory means using the first value; means for determining that the first value is a member of a first set of values, if the location contains a certain value, and wherein the second setting means includes means for selecting a pattern, using the first value; and second means for determining whether the second value substantially matches the pattern; third means for setting the output pixel, in accordance with whether the second value substantially matches the pattern.
Claim 12
Dependent Claim
102 words
The system of claim 8, wherein the determining means includes a first memory means; means for reading a location in the first memory means using the first value; means for determining that the first value is a member of a first set of values, if the location contains a certain value, and wherein the second setting means includes a second memory means; means for reading a plurality of locations in the second table using the first value, to produce a plurality of masks; and third means for setting the output pixel, in accordance with the second value and the plurality of masks.
Claim 13
Dependent Claim
114 words
The system of claim 10, wherein the plurality of masks include first, second, and third masks each having a digit corresponding to each pixel in the second set of pixels, respectively, and the second setting means includes means for comparing the second value to the first mask to produce a first result; means for comparing the second value to the second mask to produce a second result; means for comparing the second value to the third mask to produce a third result; and means for reading a location in a third memory means using the first value to produce an intensity value for the output pixel, depending on the first, second, and third results.
Claim 14
Dependent Claim
122 words
The system of claim 10, wherein the plurality of masks include first, second, and third masks each having a digit corresponding to each pixel in the second set of pixels, respectively, and the second setting means includes first means for ANDing the second value with the first mask to produce a first result; second means for ANDing the second value with the second mask to produce a second result; third means for ANDing the second value to the third mask to produce a third result; means for reading a location in a third memory means using the first value to produce an intensity value for the output pixel, if the first and second results are nonzero and the third result is zero.
Claim 15
Dependent Claim
35 words
The system of claim 8, wherein the second forming means includes means for forming the second value from intensities of a second set of pixels that are mutually exclusive from the first set of pixels.
Claim 16
Dependent Claim
33 words
The system of claim 8, wherein the second forming means includes means for forming the second value from intensities of a second set of pixels that are surrounding the first set of pixels.
References Cited (Backward Citations)
US4259694A
Cited
US4698778A
Cited
US4703363A
Cited
US4817174A
Cited
US5036405A
Cited
US4805033A
Cited
US4866534A
Cited
US5126726A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-01 | 2002-08-03 | 2003-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-01 | 2006-08-03 | 2007-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-01 | 2010-08-03 | 2011-02-02 | $7700.00 | Window Closed / Lapsed |