Method and apparatus for video stabilization
AssigneesMultivision Intelligent Surveillance (HK) Ltd., The University of Hong Kong
InventorsHing Chung, Yuk Lun Chin, Kam Chow, Chun Leung, Fuk Mak
Life of this patent
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Abstract
A method and an apparatus for video stabilization is disclosed for detecting and eliminating unwanted camera motion from a sequence of video images. Motion vectors are first generated based on sample points using a block matching technique, from which a number of possible camera motions are estimated. Among the estimated camera motions, unwanted or undesirable camera motions are then detected and parameterized. A frame remapping process is then applied to relocate the pixels in the current frame, which acts in opposition to the dislocation of pixels due to unwanted camera motions in order to achieve video stabilization.
Claims27
A video stabilization apparatus comprising:
- memory for storing current frame data representative of a current frame and reference frame data representative of a reference frame;
- and
- one or more processors connected to the memory and operable (a) to retrieve the current frame data and the reference frame data;
- (b) to calculate motion vectors based on the current frame data and the reference frame data;
- (c) to estimate a set of motion parameters based on the motion vectors;
- (d) to select a final motion parameter from the set of motion parameters, and (e) to generate, based on the final motion parameter, output frame data representative of an output frame.
A method of video stabilization comprising:
- storing current frame data representative of a current frame and reference frame data representative of a reference frame;
- calculating motion vectors based on the current frame data and the reference frame data;
- estimating a set of motion parameters based on the motion vectors;
- selecting a final motion parameter from the set of motion parameters;
- and
- generating, based on the final motion parameter, output frame data representative of an output frame.
A method of camera motion estimation comprising:
- selecting a subset of sample points from a set of sample points, the subset including at least three non-collinear sample points;
- calculating motion parameters based on the selected subset of sample points and motion vectors associated with the selected subset of sample points;
- and
- repeating the selection of the sample points and the calculating of the motion parameters, thereby obtaining a set of camera motion parameters, for no more than a pre-defined number of iterations.
A method comprising:
- forming a plurality of at least partially remapped video frames, including forming different ones of the plurality of remapped video frames based on different ones of a plurality of camera motion parameters;
- determining respective degrees of similarity between the remapped video frames and a reference frame;
- selecting as a final camera motion parameter the camera motion parameter associated with the remapped video frame that a highest degree of similarity to the reference frame;
- and
- if the highest degree of similarity obtained during the determining is indicative of an estimated camera motion that does not appear to include unwanted or undesirable motions, setting the final camera motion parameter to have no effect on a frame remapping process.
A method of video stabilization comprising:
- storing current frame data representative of a current frame and reference frame data representative of a reference frame;
- calculating a motion parameter based on the current frame data and the reference frame data;
- generating, based on the motion parameter, output frame data representative of an output frame;
- determining a degree of similarity between the output frame and the reference frame;
- and
- generating a new reference frame using the output frame data if the degree of similarity is above a predetermined threshold.
Dependencies are inferred from the claim text.