Real-time face tracking in a digital image acquisition device
First Claim
1. A method of tracking faces in an image stream with a digital image acquisition device, comprising:
- a. receiving an acquired image from an image stream including one or more face regions;
b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image;
c. calculating a corresponding integral image for a least a portion of said sub-sampled image;
d. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions;
e. adjusting a resolution for sub-sampling a next acquired image;
f. repeating a. to e. at the adjusted resolution periodically on a selected plurality of images of an image stream including a main acquired image chronologically following a plurality of images of said selected plurality of images.
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Accused Products
Abstract
An image processing apparatus for tracking faces in an image stream iteratively receives an acquired image from the image stream potentially including one or more face regions. The acquired image is sub-sampled at a specified resolution to provide a sub-sampled image. An integral image is then calculated for a least a portion of the sub-sampled image. Fixed size face detection is applied to at least a portion of the integral image to provide a set of candidate face regions. Responsive to the set of candidate face regions produced and any previously detected candidate face regions, the resolution is adjusted for sub-sampling a subsequent acquired image.
215 Citations
59 Claims
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1. A method of tracking faces in an image stream with a digital image acquisition device, comprising:
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a. receiving an acquired image from an image stream including one or more face regions; b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image; c. calculating a corresponding integral image for a least a portion of said sub-sampled image; d. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions; e. adjusting a resolution for sub-sampling a next acquired image; f. repeating a. to e. at the adjusted resolution periodically on a selected plurality of images of an image stream including a main acquired image chronologically following a plurality of images of said selected plurality of images. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. An image processing apparatus for tracking faces in an image stream comprising one or more processors and one or more digital storage media having digitally-encoded instructions embedded therein for programming the one or more processors to perform an iterative method of tracking faces in an image stream, the method comprising:
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a. receiving an acquired image from an image stream including one or more face regions; b. sub-sampling said acquired image at a specified resolution to provide a sub-sampled image; c. calculating a corresponding integral image for a least a portion of said sub-sampled image; d. applying face detection to at least a portion of said integral image to provide a set of one or more candidate face regions; e. adjusting a resolution for sub-sampling a next acquired image; f. repeating a. to e. at the adjusted resolution periodically on a selected plurality of images of an image stream including a main acquired image chronologically following a plurality of images of said selected plurality of images. - View Dependent Claims (31)
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32. A method of detecting faces in an image stream using a digital image acquisition device, comprising:
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a. determining an orientation of a digital image acquisition device for at least one image of an image stream; b. acquiring the image, which includes one or more face regions, from said image stream; and c. applying face detection to at least a portion of said acquired image to provide a set of one or more candidate face regions according to said determined orientation, and wherein said face detection selectively employs a sequence of classifiers from an available plurality of classifier sequences, each classifier sequence being at a given orientation. - View Dependent Claims (33, 34)
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35. An image processing apparatus including one or more processors and one or more digital storage media having digitally-encoded instructions embedded therein for programming the one or more processors to perform an iterative method of detecting faces in an image stream, the method comprising:
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a. determining an orientation of a digital image acquisition device for at least one image of an image stream; b. acquiring the image, which includes one or more face regions, from said image stream; and c. applying face detection to at least a portion of said acquired image to provide a set of one or more candidate face regions according to said determined orientation, and wherein said face detection selectively employs a sequence of classifiers from an available plurality of classifier sequences, each classifier sequence being at a given orientation. - View Dependent Claims (36, 37, 38, 39, 40)
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41. A method of detecting faces in an image stream using a digital image acquisition device comprising:
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a. receiving a first acquired image from said image stream including one or more face regions; b. applying face detection to at least a portion of said first acquired image to provide a set of one or more candidate face regions each having a probability of being a face region; c. tracking candidate face regions across a plurality of images of said image stream including said first acquired image; and d. responsive to a probability of a tracked face region dropping by more than a threshold rate with respect to time, activating an enhancement sub-system for a period of time to improve the probability of said face detection detecting a candidate face region. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50)
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51. A digital image acquisition device for detecting faces in an image stream comprising:
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a. means for receiving a first acquired image from said image stream including one or more face regions; b. means for applying face detection to at least a portion of said first acquired image to provide a set of one or more candidate face regions each having a probability of being a face region; c. means for tracking candidate face regions across a plurality of images of said image stream including said first acquired image; and d. means, responsive to a probability of a tracked face region dropping by more than a threshold rate with respect to time, for activating an enhancement sub-system for a period of time to improve the probability of said face detection detecting a candidate face region.
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52. An image processing apparatus including one or more processors and one or more digital storage media having digitally-encoded instructions embedded therein for programming the one or more processors to perform a method of detecting faces in an image stream using a digital image acquisition device, the method comprising:
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a. receiving a first acquired image from said image stream including one or more face regions; b. applying face detection to at least a portion of said first acquired image to provide a set of one or more candidate face regions each having a probability of being a face region; c. tracking candidate face regions across a plurality of images of said image stream including said first acquired image; and d. responsive to a probability of a tracked face region dropping by more than a threshold rate with respect to time, activating an enhancement sub-system for a period of time to improve the probability of said face detection detecting a candidate face region. - View Dependent Claims (53, 54, 55, 56, 57, 58, 59)
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Specification