Patent US5293579A successfully refreshed from Google Patents.
US5293579A
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Method and apparatus for smoothing jagged edges in a graphics display
Assignee: Ray Dream Inc
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Filing: 1992-02-18
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Granted: 1994-03-08
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Expires: 2012-02-18
Abstract
Abstract A method and apparatus for detection and smoothing of jagged edges in a graphics display is described. The edge detection and smoothing is done using only a pixel-map representation of the pixel colors of the image as input. Edges are detected based upon the color representations of certain groups of pixels. Smoothing of the edges is accomplished by adjusting the color of certain pixels in the region of a detected edge. Edges are detected by successively scanning either sets of two rows or sets of two columns of pixels. Edge detection occurs during the row or column scans by discerning certain sequences of color changes between pairs of adjacent pixels. Color changes are detected only if certain threshold changes in color occur between pairs of adjacent pixels. Unless the threshold color change is exceeded, pixels are considered to be the same color and no edge is detected. Jagged edges are detected and smoothed regardless of the type of color representation used in the pixel-map. The pixel-map may represent, for instance, the color of each pixel as a combination of shades of red, green or blue, a combination of varying degrees of hue, brightness and saturation, or some other combination.
Inventors
- 👤 John F. Stockholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:25
CPC Classifications
G; G06; G06T; G06T11/00; G06T11/20; G06T11/23
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
361 words
A method for detecting jagged edges in an image represented by a rectangular array of pixels, the method comprising the steps of: accessing a first group of pixel data from a data storage device, the first group of pixel data comprising a first set of pixel data and a second set of pixel data, wherein: the first and second sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column; determining a first difference between the value of the pixel data for a first pixel of the first set and the value of the pixel data for a first pixel of the second set; determining a second difference between the value of the pixel data for a second pixel of the first set and the value of the pixel data for a second pixel of the second set; determining, based upon the comparison of the first and second sets of pixel data, whether a jagged edge is present in the image; accessing a second group of pixel data from the data storage device, the second group of pixel data comprising a third set of pixel data and a fourth set of pixel data, wherein: the third and fourth sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column; determining a third difference between the value of the pixel data for a first pixel of the third set and the value of the pixel data for a first pixel of the fourth set; determining a fourth difference between the value of the pixel data for a second pixel of the third set and the value of the pixel data for a second pixel of the fourth set; and determining, based upon the comparison of the first and second sets of pixel data, and the comparison of the third and fourth sets of pixel data, the type of jagged edge present in the image.
Claim 2
Independent Claim
361 words
A method for detecting jagged edges in an image represented by a rectangular array of pixels, the method comprising the steps of: accessing a first group of pixel data from a data storage device, the first group of pixel data comprising a first set of pixel data and a second set of pixel data, wherein: the first and second sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column; determining a first difference between the value of the pixel data for a first pixel of the first set and the value of the pixel data for a first pixel of the second set; determining a second difference between the value of the pixel data for a second pixel of the first set and the value of the pixel data for a second pixel of the second set; determining, based upon the comparison of the first and second sets of pixel data, whether a jagged edge is present in the image; accessing a second group of pixel data from the data storage device, the second group of pixel data comprising a third set of pixel data and a fourth set of pixel data, wherein: the third and fourth sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column; determining a third difference between the value of the pixel data for a first pixel of the third set and the value of the pixel data for a first pixel of the fourth set; determining a fourth difference between the value of the pixel data for a second pixel of the third set and the value of the pixel data for a second pixel of the fourth set; and determining, based upon the comparison of the first and second sets of pixel data, and the comparison of the third and fourth sets of pixel data, the type of jagged edge present in the image.
Claim 3
Dependent Claim
149 words
A method as in claim 1, wherein: the step of determining whether a jagged edge is present in the image further comprises: comparing the first difference to a predetermined threshold value; comparing the second difference to a predetermined threshold value; and determining that a jagged edge is present in the image if exactly one of the first or second difference is greater than the threshold value; the step of determining the type of jagged edge present in the image further comprises: comparing the third difference to a predetermined threshold value; comparing the fourth difference to a predetermined threshold value, exactly one of the third or fourth difference being greater than the threshold value; and determining the type of jagged edge by determining which of the first and second differences is greater than the threshold value and which of the third and fourth differences is greater than the threshold value.
Claim 4
Dependent Claim
30 words
A method as in claim 2, wherein the types of jagged edges include a top jagged edge, a bottom jagged edge, a descending jagged edge and an ascending jagged edge.
Claim 5
Independent Claim
374 words
A system for detecting jagged edges in an image represented by a rectangular array of pixels, the system comprising: means for accessing a first group of pixel data from a data storage device, the first group of pixel data comprising a first set of pixel data and a second set of pixel data; the first and second sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column. means for determining a first difference between the value of the pixel data for a first pixel of the first set and the value of the pixel data for a first pixel of the second set; means for determining a second difference between the value of the pixel data for a second pixel of the first set and the value of the pixel data for a second pixel of the second set; means for determining, based upon the comparison of the first and second sets of pixel data, whether a jagged edge is present in the image; means for accessing a second group of pixel data from the data storage device, the second group of pixel data comprising a third set of pixel data and a fourth set of pixel data, wherein: the third and fourth sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column means for determining a third difference between the value of the pixel data for a first pixel of the third set and the value of the pixel data for a first pixel of the fourth set; and means for determining a fourth difference between the value of the pixel data for a second pixel of the third set and the value of the pixel data for a second pixel of the fourth set; and means for determining, based upon the comparison of the first and second sets of pixel data, and the comparison of the third and fourth sets of pixel data, the type of jagged edge present in the image.
Claim 6
Independent Claim
374 words
A system for detecting jagged edges in an image represented by a rectangular array of pixels, the system comprising: means for accessing a first group of pixel data from a data storage device, the first group of pixel data comprising a first set of pixel data and a second set of pixel data; the first and second sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column. means for determining a first difference between the value of the pixel data for a first pixel of the first set and the value of the pixel data for a first pixel of the second set; means for determining a second difference between the value of the pixel data for a second pixel of the first set and the value of the pixel data for a second pixel of the second set; means for determining, based upon the comparison of the first and second sets of pixel data, whether a jagged edge is present in the image; means for accessing a second group of pixel data from the data storage device, the second group of pixel data comprising a third set of pixel data and a fourth set of pixel data, wherein: the third and fourth sets of pixel data are successive sets of pixel data from adjacent columns or adjacent rows; and the successive sets of pixel data comprise pixel data for two adjacent pixels in each row or column means for determining a third difference between the value of the pixel data for a first pixel of the third set and the value of the pixel data for a first pixel of the fourth set; and means for determining a fourth difference between the value of the pixel data for a second pixel of the third set and the value of the pixel data for a second pixel of the fourth set; and means for determining, based upon the comparison of the first and second sets of pixel data, and the comparison of the third and fourth sets of pixel data, the type of jagged edge present in the image.
Claim 7
Dependent Claim
161 words
A system as in claim 4, wherein: the means for determining whether a jagged edge is present in the image further comprises: means for comparing the first difference to a predetermined threshold value; means for comparing the second difference to a predetermined threshold value; and means for determining that a jagged edge is present in the image if exactly one of the first or second difference is greater than the threshold value; the means for determining the type of jagged edge present in the image further comprises: means for comparing the third difference to a predetermined threshold value; means for comparing the fourth difference to a predetermined threshold value, exactly one of the third or fourth difference being greater than the threshold value; and means for determining the type of jagged edge by determining which of the first and second differences is greater than the threshold value and which of the third and fourth differences is greater than the threshold value.
Claim 8
Dependent Claim
30 words
A system as in claim 5, wherein the types of jagged edges include a top jagged edge, a bottom jagged edge, a descending jagged edge and an ascending jagged edge.
References Cited (Backward Citations)
US4506382A
Cited
US4742399A
Cited
US4827533A
Cited
US5023919A
Cited
US5093870A
Cited
US5091967A
Cited
US5050227A
Cited
US5105472A
Cited
US5060082A
Cited
US5111285A
Cited
US5091973A
Cited
US5151787A
Cited
US5204918A
Cited
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| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |