Patent US5446804A successfully refreshed from Google Patents.
US5446804A
Expired / Lapsed
US
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Magnifying digital image using edge mapping
Assignee: Hewlett Packard Development Co LP
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Filing: 1994-04-14
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Granted: 1995-08-29
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Expires: 2014-04-14
Abstract
Abstract A method of magnifying a digital image based on an edge map. The image has many original pixels, with each pixel having a level, and the locations of the pixels having a resolution. The method to magnify the image includes the steps of producing an edge map with many boundaries from the digital image, projecting the edge map onto the digital image, generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels without crossing any boundaries set by the edge map, and expanding the distances between the pixels so that the resolution of the locations of the pixels becomes the same as the original pixels. In another preferred embodiment, the original digital image is enlarged to the size of the magnified image by extending proportionally the locations of the original pixels. Then the edge map is produced and projected onto the enlarged image to generate additional pixels. After the step of generating, the resolution of the locations of the pixels becomes the same as the original pixels.
Inventors
- 👤 Jan P. Allebach
- 👤 Ping W. Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:54
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/40; G06T3/403; G06T3/4023; G06T7/00; G06T7/10; G06T7/12
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
132 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level, the locations of the pixels having a resolution, the method comprising the steps of: producing an edge map with a plurality of boundaries by analyzing the digital image to pick locations in neighborhoods where levels change significantly and then connecting the picked locations to form edges; projecting the edge map onto the digital image; and generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; such that the total number of additional pixels is related to the number of original pixels and the magnification.
Claim 2
Independent Claim
132 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level, the locations of the pixels having a resolution, the method comprising the steps of: producing an edge map with a plurality of boundaries by analyzing the digital image to pick locations in neighborhoods where levels change significantly and then connecting the picked locations to form edges; projecting the edge map onto the digital image; and generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; such that the total number of additional pixels is related to the number of original pixels and the magnification.
Claim 3
Dependent Claim
55 words
A method as recited in claim 1 further comprising the step of: expanding, after the step of generating, the distances between all the pixels to generate the magnified image so that the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image.
Claim 4
Independent Claim
205 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level, the locations of the pixels having a resolution, the method comprising the steps of: enlarging the digital image to the size of the magnified image by expanding proportionally the distances separating the original pixels; producing an edge map with a plurality of boundaries by analyzing the digital image that has been enlarged to pick locations in neighborhoods where levels change significantly and then connecting the picked locations to form edges; projecting the edge map onto the digital image that has been enlarged; and generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; such that: the total number of additional pixels is related to the number of original pixels and the magnification; after the step of generating, the digital image that has been enlarged becomes the magnified image; and the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image before it was enlarged.
Claim 5
Independent Claim
205 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level, the locations of the pixels having a resolution, the method comprising the steps of: enlarging the digital image to the size of the magnified image by expanding proportionally the distances separating the original pixels; producing an edge map with a plurality of boundaries by analyzing the digital image that has been enlarged to pick locations in neighborhoods where levels change significantly and then connecting the picked locations to form edges; projecting the edge map onto the digital image that has been enlarged; and generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; such that: the total number of additional pixels is related to the number of original pixels and the magnification; after the step of generating, the digital image that has been enlarged becomes the magnified image; and the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image before it was enlarged.
Claim 6
Independent Claim
191 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level the locations of the pixels having a resolution, the method comprising the steps of: producing an edge map with a plurality of boundaries by: analyzing the digital image to pick locations in neighborhoods where levels change significantly; and connecting any two picked locations to form an edge if the distance between the locations is less than or equal to the minimum distance between two adjacent original pixels; projecting the edge map onto the digital image; generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; and expanding the distances between all the pixels to generate the magnified image so that the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image; such that the total number of additional pixels is related to the number of original pixels and the magnification.
Claim 7
Independent Claim
191 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level the locations of the pixels having a resolution, the method comprising the steps of: producing an edge map with a plurality of boundaries by: analyzing the digital image to pick locations in neighborhoods where levels change significantly; and connecting any two picked locations to form an edge if the distance between the locations is less than or equal to the minimum distance between two adjacent original pixels; projecting the edge map onto the digital image; generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; and expanding the distances between all the pixels to generate the magnified image so that the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image; such that the total number of additional pixels is related to the number of original pixels and the magnification.
Claim 8
Dependent Claim
70 words
A method as recited in claim 4 wherein the step of analyzing further comprises: representing each pixel by an impulse function with its magnitude being equal to the level of its corresponding pixel; selecting a singly-peaked continuous function; differentiating the selected function twice; convolving in selected locations in the digital image the differentiated function with the impulse functions; and picking the locations where the convolving step generates substantially a zero.
Claim 9
Dependent Claim
70 words
A method as recited in claim 4 wherein the step of analyzing further comprises: representing each pixel by an impulse function with its magnitude being equal to the level of its corresponding pixel; selecting a singly-peaked continuous function; convolving at selected locations in the digital image the selected function with the impulse functions; differentiating twice the convolved results; and picking the locations where the differentiating step generates substantially a zero.
Claim 10
Dependent Claim
15 words
A method as recited in claim 5 wherein the continuous function is a Gaussian function.
Claim 11
Dependent Claim
33 words
A method as recited in claim 5 wherein the step of picking further comprises the step of thresholding, which removes any picked location with its local level variances less than a pre-selected value.
Claim 12
Dependent Claim
33 words
A method as recited in claim 6 wherein the step of picking further comprises the step of thresholding, which removes any picked location with its local level variances less than a pre-selected value.
Claim 13
Dependent Claim
78 words
A method as recited in claim 5 wherein the step of picking further comprises the steps of: forming temporary pixels at selected locations in the digital image; evaluating the levels at the temporary pixels from the results of the convolving step; comparing the levels of adjacent temporary pixels; selecting those pairs of adjacent temporary pixels whose levels change sign; and choosing each location based on the temporary pixel, from every selected pair, whose level is closer to zero.
Claim 14
Dependent Claim
78 words
A method as recited in claim 6 wherein the step of picking further comprises the steps of: forming temporary pixels at selected locations in the digital image; evaluating the levels at the temporary pixels from the results of the differentiating step; comparing the levels of adjacent temporary pixels; selecting those pairs of adjacent temporary pixels whose levels change sign; and choosing each location based on the temporary pixel, from every selected pair, whose level is closer to zero.
Claim 15
Dependent Claim
44 words
A method as recited in claim 2 wherein the step of generating further comprises the step of interpolating the levels of one or more original pixels to create the levels of one or more additional pixels in the immediate neighborhood of the original pixels.
Claim 16
Dependent Claim
21 words
A method as recited in claim 1 wherein the image is two-dimensional and the edge map includes one or more lines.
Claim 17
Dependent Claim
21 words
A method as recited in claim 1 wherein the image is three-dimensional and the edge map includes one or more surfaces.
Claim 18
Dependent Claim
13 words
A method as recited in claim 1 wherein the image is in monochrome.
Claim 19
Dependent Claim
13 words
A method as recited in claim 1 wherein the image is in color.
Claim 20
Independent Claim
230 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level, the locations of the pixels having a resolution, the method comprising the steps of: producing an edge map with a plurality of boundaries from the digital image; projecting the edge map onto the digital image; generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; selecting a window size; for every additional pixel in the immediate neighborhood of the boundaries, centering the window to that additional pixel, calculating the average level of the original pixels within the window and on the same side of the boundary as the additional pixel, and replacing the level of the additional pixel with the average level if the level of the additional pixel differs by more than a certain value from the average; and expanding, after the step of generating, the distances between all the pixels to generate the magnified image so that the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image; such that the total number of additional pixels is related to the number of original pixels and the magnification.
Claim 21
Independent Claim
230 words
A method of magnifying a digital image with a plurality of original pixels to form a magnified image, each pixel having a level, the locations of the pixels having a resolution, the method comprising the steps of: producing an edge map with a plurality of boundaries from the digital image; projecting the edge map onto the digital image; generating one or more additional pixels in locations among the original pixels by manipulating the levels of one or more original pixels that do not have among them any boundaries set by the edge map; selecting a window size; for every additional pixel in the immediate neighborhood of the boundaries, centering the window to that additional pixel, calculating the average level of the original pixels within the window and on the same side of the boundary as the additional pixel, and replacing the level of the additional pixel with the average level if the level of the additional pixel differs by more than a certain value from the average; and expanding, after the step of generating, the distances between all the pixels to generate the magnified image so that the resolution of the locations of all the pixels in the magnified image becomes the same as the original pixels in the digital image; such that the total number of additional pixels is related to the number of original pixels and the magnification.
Claim 22
Dependent Claim
59 words
A method as recited in claim 1 wherein the image is a halftone image, and the method further comprising two additional steps, inverse halftoning the image to form a continuous image before performing the method as recited in claim 1; and halftoning the resultant image to form a halftone image after performing the method as recited in claim 1.
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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) | 1998-08-28 | 1999-02-27 | 1999-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-28 | 2003-02-27 | 2003-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-28 | 2007-02-27 | 2007-08-29 | $7700.00 | Window Closed / Lapsed |