US6728401B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Red-eye removal using color image processing
Assignee: Synaptics Inc
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Filing: 2000-08-17
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Granted: 2004-04-27
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Expires: 2020-08-17
Abstract
Abstract A color processing system is provided that corrects color artifacts such as red eye typically formed in images from a camera flash. An image is captured or processed by inputting the image into the system. To correct red eye artifacts, a "redness" mask is computed by calculating the colorimetric distance, in an approximately perceptually linear color space, between a prototypical reference "red eye" color and each pixel of the image, or a selected portion thereof, containing the red eye. Each pixel of the redness mask is then reduced to one of two values by comparing the calculated colorimetric distance recorded by each mask pixel to a threshold value. Various filtering, morphological, and blob analysis techniques may be applied to the mask to eliminate noise, reduce errors, and facilitate a more natural look. The mask serves to identify pixels in the color image needing correction, and further serves to identify the amount of correction needed. Pixels identified as having red-eye artifacts are modified to a substantially monochrome color. The bright, substantially white, specular reflection of the eye, however, is preserved.
Inventors
- 👤 Jon Y. Hardeberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:35
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/20; G06T5/30; G06T5/70; G06T5/77; G06T7/00; G06T7/10; G06T7/11; G06T7/155; G06T7/90; G06V; G06V40/00; G06V40/10; G06V40/18; G06V40/193; H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/62; H04N1/624; G06T2207/00; G06T2207/10; G06T2207/10024; G06T2207/30; G06T2207/30004; G06T2207/30041
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
262 words
An artifact correction system that corrects an artifact having a plurality of color characteristics comprising: image capture circuitry that captures a color image; signal processing circuitry that receives the color image from the image capture circuitry, compares at least a portion of the color image to at least one reference color characteristic to identify the artifact, and modifies at least one of the plurality of color characteristics of the artifact; memory that stores the color image in its raw and processed states; and wherein the signal processing circuitry compares the plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to at least one threshold value to compute a mask representing a plurality of pixels, where each pixel is represented by one of only two discrete end values, a plurality of pixel blobs are created having common values, the artifact has an expected pattern, the signal processing circuitry performs morphological, blob-detection, and pattern-recognition operations on the mask to select an artifact-identifying blob out of the plurality of pixel blobs corresponding to the expected pattern of the artifact, the artifact-identifying blob of the mask has a periphery, the signal processing circuitry performs a smoothing operation on the artifact-identifying blob to introduce a plurality of intermediate values to the mask along the periphery of the artifact-identifying blob, and the signal processing circuitry modifies the at least one of the plurality of color characteristics of the artifact in proportion to the end values and intermediate values that represent the pixels of the mask.
Claim 2
Dependent Claim
262 words
An artifact correction system that corrects an artifact having a plurality of color characteristics comprising: image capture circuitry that captures a color image; signal processing circuitry that receives the color image from the image capture circuitry, compares at least a portion of the color image to at least one reference color characteristic to identify the artifact, and modifies at least one of the plurality of color characteristics of the artifact; memory that stores the color image in its raw and processed states; and wherein the signal processing circuitry compares the plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to at least one threshold value to compute a mask representing a plurality of pixels, where each pixel is represented by one of only two discrete end values, a plurality of pixel blobs are created having common values, the artifact has an expected pattern, the signal processing circuitry performs morphological, blob-detection, and pattern-recognition operations on the mask to select an artifact-identifying blob out of the plurality of pixel blobs corresponding to the expected pattern of the artifact, the artifact-identifying blob of the mask has a periphery, the signal processing circuitry performs a smoothing operation on the artifact-identifying blob to introduce a plurality of intermediate values to the mask along the periphery of the artifact-identifying blob, and the signal processing circuitry modifies the at least one of the plurality of color characteristics of the artifact in proportion to the end values and intermediate values that represent the pixels of the mask.
Claim 3
Dependent Claim
73 words
The artifact correction system of claim 1 , wherein the at least a portion of the color image comprises a plurality of pixels having three additive color components; where the signal processing circuitry transforms the three additive color components of the pixels into chrominance and luminance components of an approximately perceptually linear color space; and where the signal processing circuitry modifies the chrominance components of the artifact to make the artifact substantially achromatic.
Claim 4
Dependent Claim
18 words
The artifact correction system of claim 1 , further comprising a camera that houses the image capture circuitry.
Claim 5
Dependent Claim
17 words
The artifact correction system of claim 3 , wherein the camera further houses the signal processing circuitry.
Claim 6
Dependent Claim
42 words
The artifact correction system of claim 1 , wherein the signal processing circuitry computes a plurality of color difference values between the at least a portion of the color image and the at least one reference color characteristic to identify the artifact.
Claim 7
Dependent Claim
28 words
The artifact correction system of claim 5 , wherein the color difference values represent qualitative color differences in a color plane of an approximately perceptually linear color space.
Claim 8
Dependent Claim
45 words
The artifact correction system of claim 1 , wherein the signal processing circuitry computes a mask representing a plurality of color difference values between the at least a portion of the color image and the at least one reference color characteristic, to identify the artifact.
Claim 9
Dependent Claim
241 words
An image processing system that corrects an artifact having a plurality of color characteristics, in a color image, comprising: signal processing circuitry that compares at least a portion of the color image to at least one reference color characteristic to identify the artifact, and modifies at least one of the plurality of color characteristics of the artifact to correct the artifact; and wherein the signal processing circuitry compares a plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to at least one threshold value to compute a mask representing a plurality of pixels, where each pixel is represented by one of only two discrete end values, a plurality of pixel blobs are created having common values, the artifact has an expected pattern, the signal processing circuitry performs morphological, blob-detection, and pattern-recognition operations on the mask to select an artifact-identifying blob out of the plurality of pixel blobs corresponding to the expected pattern of the artifact, the artifact-identifying blob of the mask has a periphery, the signal processing circuitry performs a smoothing operation on the artifact-identifying blob to introduce a plurality of intermediate values to the mask along the periphery of the artifact-identifying blob, and the signal processing circuitry modifies the at least one of the plurality of color characteristics of the artifact in proportion to the end values and intermediate values that represent the pixels of the mask.
Claim 10
Dependent Claim
241 words
An image processing system that corrects an artifact having a plurality of color characteristics, in a color image, comprising: signal processing circuitry that compares at least a portion of the color image to at least one reference color characteristic to identify the artifact, and modifies at least one of the plurality of color characteristics of the artifact to correct the artifact; and wherein the signal processing circuitry compares a plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to at least one threshold value to compute a mask representing a plurality of pixels, where each pixel is represented by one of only two discrete end values, a plurality of pixel blobs are created having common values, the artifact has an expected pattern, the signal processing circuitry performs morphological, blob-detection, and pattern-recognition operations on the mask to select an artifact-identifying blob out of the plurality of pixel blobs corresponding to the expected pattern of the artifact, the artifact-identifying blob of the mask has a periphery, the signal processing circuitry performs a smoothing operation on the artifact-identifying blob to introduce a plurality of intermediate values to the mask along the periphery of the artifact-identifying blob, and the signal processing circuitry modifies the at least one of the plurality of color characteristics of the artifact in proportion to the end values and intermediate values that represent the pixels of the mask.
Claim 11
Dependent Claim
42 words
The image processing system of claim 8 , wherein the signal processing circuitry computes a plurality of color difference values between the at least a portion of the color image and the at least one reference color characteristic to identify the artifact.
Claim 12
Dependent Claim
27 words
The image processing system of claim 8 , wherein the artifact is a red-eye artifact caused by absorption of visible light by the retina of an eye.
Claim 13
Dependent Claim
44 words
The image processing system of claim 8 , wherein the signal processing circuitry computes a mask representing a plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to identify the artifact.
Claim 14
Dependent Claim
30 words
The image processing system of claim 11 , wherein the signal processing circuitry compares the plurality of color difference values to at least one threshold value to identify the artifact.
Claim 15
Dependent Claim
28 words
The artifact correction system of claim 11 , wherein the signal processing circuitry performs morphological and blob-detection operations on the mask to identify the artifact with greater accuracy.
Claim 16
Independent Claim
212 words
A method for correcting an artifact, having a plurality of color characteristics in a color image comprising: comparing at least a portion of the color image to at least one reference color characteristic to identify the artifact; modifying at least one of the plurality of color characteristics of the artifact; comparing a plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to at least one threshold value to compute a mask representing a plurality of pixels, where each pixel is represented by one of only two discrete end values; creating a plurality of pixel blobs having common values, where the artifact has an expected pattern; performing morphological, blob-detection, and pattern-recognition operations on the mask to select an artifact-identifying blob out of the plurality of pixel blobs corresponding to the expected pattern of the artifact, the artifact-identifying blob of the mask has a periphery; performing a smoothing operation on the artifact-identifying blob to introduce a plurality of intermediate values to the mask along the periphery of the artifact-identifying blob; and modifying the at least one of the plurality of color characteristics of the artifact in proportion to the end values and intermediate values that represent the pixels of the mask.
Claim 17
Independent Claim
212 words
A method for correcting an artifact, having a plurality of color characteristics in a color image comprising: comparing at least a portion of the color image to at least one reference color characteristic to identify the artifact; modifying at least one of the plurality of color characteristics of the artifact; comparing a plurality of color difference values between at least a portion of the color image and the at least one reference color characteristic to at least one threshold value to compute a mask representing a plurality of pixels, where each pixel is represented by one of only two discrete end values; creating a plurality of pixel blobs having common values, where the artifact has an expected pattern; performing morphological, blob-detection, and pattern-recognition operations on the mask to select an artifact-identifying blob out of the plurality of pixel blobs corresponding to the expected pattern of the artifact, the artifact-identifying blob of the mask has a periphery; performing a smoothing operation on the artifact-identifying blob to introduce a plurality of intermediate values to the mask along the periphery of the artifact-identifying blob; and modifying the at least one of the plurality of color characteristics of the artifact in proportion to the end values and intermediate values that represent the pixels of the mask.
Claim 18
Dependent Claim
40 words
The method of claim 14 , further comprising computing a mask representing a plurality of color difference values between the at least a portion of the color image and the at least one reference color characteristic to identify the artifact.
Claim 19
Dependent Claim
51 words
The method of claim 14 , further comprising computing color difference values in an approximately perceptually linear color space between the at least one reference color characteristic and the at least a portion of the color image, where the at least one reference color characteristic is represented in the color space.
Claim 20
Dependent Claim
55 words
The method of claim 14 , further comprising computing a plurality of color difference values between the at least a portion of the color image and the at least one reference color characteristic, and comparing the plurality of color difference values with at least one threshold value to create a mask that identifies the artifact.
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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) | 2007-04-27 | 2007-10-27 | 2008-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-04-27 | 2011-10-27 | 2012-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-04-27 | 2015-10-27 | 2016-04-27 | $7700.00 | Window Closed / Lapsed |