US5805745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for locating a subject's lips in a facial image
Assignee: Nokia of America Corp
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Filing: 1995-06-26
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Granted: 1998-09-08
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Expires: 2015-06-26
Abstract
Abstract An embodiment of the present invention locates facial features in an image by bandpass filtering the image and then performing morphological operations followed by a thresholding operation. This initial processing identifies candidate areas where facial features may be located. The candidate areas are evaluated by classifiers to determine if a facial feature, such as an eye or mouth, has been located.
Inventors
- 👤 Hans Peter Graf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:48
CPC Classifications
G; G06; G06T; G06T11/00; H; H04; H04N; H04N7/00; H04N7/14; H04N7/141; H04N7/142; G06V; G06V40/00; G06V40/10; G06V40/16; G06V40/168; H04N19/00; H04N19/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
A method for locating a subject's lips in a image, comprising the steps of: bandpass filtering the image to produce a bandpass filtered image; morphologically processing the bandpass filtered image to produce an enhanced image by convolving the bandpass filtered image with a rectangular shape; thresholding the enhanced image to form a binary image having a plurality of connected components; and using a classifier to identify at least one connected component corresponding to the subject's mouth; determining an intensity profile along a vertical strip across the image of the subject's mouth; determining an intensity variation of the intensity profile; and comparing the intensity profile to a plurality of stored intensity profiles to locate an edge of at least one of the lips if the intensity variation is below a first threshold, and comparing the intensity profile to a second threshold to locate the edge of at least one of the lips if the intensity variation is above the first threshold.
Claim 2
Independent Claim
160 words
A method for locating a subject's lips in a image, comprising the steps of: bandpass filtering the image to produce a bandpass filtered image; morphologically processing the bandpass filtered image to produce an enhanced image by convolving the bandpass filtered image with a rectangular shape; thresholding the enhanced image to form a binary image having a plurality of connected components; and using a classifier to identify at least one connected component corresponding to the subject's mouth; determining an intensity profile along a vertical strip across the image of the subject's mouth; determining an intensity variation of the intensity profile; and comparing the intensity profile to a plurality of stored intensity profiles to locate an edge of at least one of the lips if the intensity variation is below a first threshold, and comparing the intensity profile to a second threshold to locate the edge of at least one of the lips if the intensity variation is above the first threshold.
Claim 3
Dependent Claim
31 words
The method of claim 1, wherein the step of morphologically processing comprises convolving the bandpass filtered image with a rectangular shape having vertical and horizontal dimensions similar to the subject's mouth.
Claim 4
Dependent Claim
51 words
The method of claim 1, wherein the step of bandpass filtering comprises lowpass filtering the image to produce a lowpass filtered image, highpass filtering the lowpass filtered image to produce a highpass filtered image, and subtracting the highpass filtered image from the lowpass filtered image to produce the bandpass filtered image.
Claim 5
Dependent Claim
17 words
The method of claim 1, wherein the step of using a classifier comprises using a linear classifier.
Claim 6
Dependent Claim
17 words
The method of claim 1, wherein the step of using a classifier comprises using a neural network.
Claim 7
Dependent Claim
19 words
The method of claim 1, wherein the step of bandpass filtering comprises convolving the image with a rectangular shape.
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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) | 2001-09-07 | 2002-03-09 | 2002-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-07 | 2006-03-09 | 2006-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-07 | 2010-03-09 | 2010-09-08 | $7700.00 | Window Closed / Lapsed |