US 11,983,888 B2
Image change detection device and image change detection method
Ryoma Yataka, Tokyo (JP); and Masashi Shiraishi, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
Filed on Dec. 30, 2021, as Appl. No. 17/565,900.
Application 17/565,900 is a continuation of application No. PCT/JP2019/031690, filed on Aug. 9, 2019.
Prior Publication US 2022/0122270 A1, Apr. 21, 2022
Int. Cl. G06K 9/00 (2022.01); G01S 13/89 (2006.01); G06T 3/60 (2006.01); G06T 7/20 (2017.01)
CPC G06T 7/20 (2013.01) [G01S 13/89 (2013.01); G06T 3/60 (2013.01); G06T 2207/10028 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An image change detection device comprising processing circuitry
to calculate, by a degree of change calculator implemented by the processing circuitry, a degree of change between a first subspace and a second subspace, when receiving the first subspace and the second subspace, the first subspace being a space whose bases are left singular vectors of an image in a certain period for comparison from among images generated on a basis of an observation radio wave of a radar, the second subspace being a space whose bases are left singular vectors of an image in a certain change detection period that is a period different from the certain period for comparison from among the images generated on a basis of the observation radio wave of the radar,
to determine, by a determinator implemented by the processing circuitry, whether or not the image in the certain change detection period has changed from the image in the certain period for comparison on a basis of the degree of change calculated by the degree-of-change calculator, and
to update, by a subspace updater implemented by the processing circuitry, the first subspace by rotating the first subspace so that the first subspace approaches the second subspace when the determinator determines that there has been no change,
wherein, when the determinator determines that there has been no change, the degree-of-change calculator calculates another degree of change between the first subspace which has been updated by the subspace updater and the second subspace whose bases are left singular vectors of an image in another change detection period next to the certain change detection period, and
the determinator determines that the image in the certain change detection period has changed from the image in the certain period for comparison when the degree of change calculated by the degree-of-change calculator is equal to or greater than a threshold, and determines that the image in the certain change detection period has not changed from the image in the certain period for comparison when the degree of change is less than the threshold.