JP2017143351A5 - - Google Patents

Claims (12)

A calibration device for obtaining a homography matrix from a moving image taken by a camera,
Detecting means for detecting a plurality of feature points for each of a plurality of frames in the moving image;
Determination means for determining a plurality of first feature points detected in all of the plurality of frames among a plurality of feature points of each frame detected by the detection means;
Generating means for generating a trajectory matrix based on the first coordinates of the first feature points in each of the plurality of frames;
Decomposing the trajectory matrix to generate a low rank matrix having a lower rank than the trajectory matrix, and updating the first coordinate of the first feature point in each of the plurality of frames to a second coordinate based on the low rank matrix And based on a second coordinate of the first frame of the plurality of frames and a second frame of the second frame, which is the second frame of the plurality of frames and is temporally later than the first frame, Calculating means for calculating a homography matrix of the second frame;
A calibration apparatus comprising:   The calculating means calculates the homography matrix of the second frame based on the homography matrix of the first frame, the second coordinates of the first frame, and the second coordinates of the second frame. The calibration apparatus according to claim 1, wherein:   The calibration apparatus according to claim 1, wherein the second frame is a frame subsequent to the first frame.   The calibration apparatus according to claim 1, wherein the plurality of frames are temporally continuous frames.   The calculation unit performs the matrix decomposition under a condition that a Frobenius norm of a matrix obtained by subtracting the low rank matrix from the trajectory matrix is a first value or less. The calibration apparatus according to item 1.   The calibration apparatus according to claim 5, wherein the calculation unit performs the matrix decomposition so that a nuclear norm of the low rank matrix is minimized.   The calculation means generates the low rank matrix and the sparse matrix by the matrix decomposition, and has a condition that a Frobenius norm of a matrix obtained by subtracting the low rank matrix and the sparse matrix from the trajectory matrix is not more than a first value. The calibration apparatus according to claim 1, wherein the matrix decomposition is performed.   The calculation means performs the matrix decomposition so that a sum of a value obtained by multiplying an L1 norm of the sparse matrix by a second value and a kernel norm of the low rank matrix is minimized. 8. The calibration device according to 7.   The calculation means holds real space coordinates of a reference position, and converts the real space coordinates of the reference position into pixel positions in the second frame using the calculated homography matrix of the second frame. 9. It is determined whether or not a distance between the converted pixel position and a pixel position corresponding to the reference position in the second frame is equal to or smaller than a threshold value. The calibration device according to item. A calibration device for obtaining a homography matrix from a moving image taken by a camera,
Detecting means for detecting a plurality of feature points for each of a plurality of frames in the moving image;
First determination means for determining a plurality of first feature points detected in all of the plurality of frames among a plurality of feature points of each frame detected by the detection means;
Second determination means for respectively determining trajectories of the plurality of first feature points across the plurality of frames;
Third determination means for determining a change in the shooting direction of the camera based on the trajectories of the plurality of first feature points;
Calculation means for calculating a homography matrix of at least one frame of the plurality of frames based on a change in the shooting direction of the camera determined by the third determination means;
A calibration apparatus comprising: A calibration method in a calibration device for obtaining a homography matrix from a moving image taken by a camera,
A detection step of detecting a plurality of feature points for each of a plurality of frames in the moving image;
A determination step of determining a plurality of first feature points detected in all of the plurality of frames among a plurality of feature points of each frame detected in the detection step;
Generating a trajectory matrix based on the first coordinates of the first feature points in each of the plurality of frames;
Decomposing the trajectory matrix to generate a low rank matrix having a lower rank than the trajectory matrix, and updating the first coordinate of the first feature point in each of the plurality of frames to a second coordinate based on the low rank matrix , Based on a second coordinate of a first frame of the plurality of frames and a second coordinate of a second frame that is a second frame of the plurality of frames and that is temporally later than the first frame. A calculation step of calculating a homography matrix of two frames;
A calibration method comprising: Program for causing a computer to function as the calibration apparatus according to claims 1 to 1 wherein one of 10.