Method and device for stabilizing video sequences, related video-capture apparatus and computer-program product
AssigneeSTMicroelectronics S.r.l.
InventorsGiuseppe Spampinato, Arcangelo Ranieri Bruna
Life of this patent
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Abstract
According to an embodiment, a sequence of video frames as produced in a video-capture apparatus such as a video camera is stabilized against hand shaking or vibration by:—subjecting a pair of frames in the sequence to feature extraction and matching to produce a set of matched features;—subjecting the set of matched features to an outlier removal step; and—generating stabilized frames via motion-model estimation based on features resulting from outlier removal. Motion-model estimation is performed based on matched features having passed a zone-of-interest test confirmative that the matched features passing the test are distributed over a plurality of zones across the frames.
Claims15
An apparatus, comprising:
- a comparator configured to identify
- features of a first image, and
- features of a second image that match the features of the first image, wherein the features of the second image that match the features of the first image define a set of matched features;
- a stabilizer configured to generate stabilized frames through motion model estimation based on inlier features having passed a zone-of-interest test that confirms that the inlier features are distributed over a plurality of zones across the first and second images;
- and
- an outlier remover configured:
- to identify as an outlier feature any outlying feature of the first and second images identified by the comparator;
- to identify as an inlier feature any other feature of the first and second images identified by the comparator;
- and
- to provide the inlier features to the stabilizer.
An apparatus, comprising:
- a comparator configured to identify
- features of a first image, and
- features of a second image that match the features of the first image;
- a stabilizer configured to stabilize a motion of one of the first and second images
- if a distribution of the features of the first image meets a first criterion, and
- if a distribution of the features of the second image meets a second criterion;
- a first outlier remover configured,
- to identify as a first outlier feature any outlying feature of the first and second images identified by the comparator,
- to identify as an inlier feature any other feature of the first and second images identified by the comparator;
- a distribution detector configured
- to determine if the distribution of the inlier features of the first image meets the first criterion,
- to determine if the distribution of the inlier features of the second image meets the second criterion,
- to provide the inlier features of the first and second images to the stabilizer if the distribution of the features of the first image meets the first criterion and the distribution of the features of the second image meets the second criterion,
- to provide the first outlier features to a second outlier remover if a number of the first outlier features is greater than a threshold, and the distribution of the features of the first image does not meet the first criterion or the distribution of the features of the second image does not meet the second criterion, and
- to bypass the stabilizer if the number of first outlier features is less than the threshold, and the distribution of the features of the first image does not meet the first criterion or the distribution of the features of the second image does not meet the second criterion;
- and
- the second outlier remover is configured
- to identify as a second outlier feature any outlying first outlier feature of the first and second images, and
- to provide to the distribution detector as a respective inlier feature each of the second outlier features.
A method of stabilizing a sequence of input video frames, comprising:
- performing feature extraction on a pair of input video frames in the sequence to produce extracted features for the pair of input video frames;
- performing feature matching on the extracted features to produce a set of matched features;
- performing outlier removal on the set of matched features to produce an inlier set of matched features;
- and
- generating stabilized frames through motion model estimation based on the inlier set of matched features, the motion model estimation being based on the inlier set of matched features having passed a zone-of-interest test that confirms that the inlier set of matched features that pass the zone-of-interest test are distributed over a plurality of zones across the pair of input video frames.
The method of 4, wherein generating stabilized frames through motion model estimation involves noise filtering by obtaining the parameter vector of the model by Least Squares processing.
Dependencies are inferred from the claim text.