US 12,406,462 B2
Method and device for detecting bad points in video and computer readable medium
Dan Zhu, Beijing (CN); and Ran Duan, Beijing (CN)
Assigned to BOE TECHNOLOGY GROUP CO., LTD., Beijing (CN)
Appl. No. 17/771,941
Filed by BOE TECHNOLOGY GROUP CO., LTD., Beijing (CN)
PCT Filed Jul. 5, 2021, PCT No. PCT/CN2021/104492
§ 371(c)(1), (2) Date Apr. 26, 2022,
PCT Pub. No. WO2022/042040, PCT Pub. Date Mar. 3, 2022.
Claims priority of application No. 202010862824.5 (CN), filed on Aug. 25, 2020.
Prior Publication US 2022/0377265 A1, Nov. 24, 2022
Int. Cl. G06V 10/44 (2022.01); G06T 5/50 (2006.01); G06V 10/28 (2022.01)
CPC G06V 10/443 (2022.01) [G06T 5/50 (2013.01); G06V 10/28 (2022.01); G06T 2207/20224 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of detecting bad points in a video, comprising:
performing extreme filtering respectively on a first frame of image, a second frame of image and a third frame of image which are sequentially and continuously in the video, to obtain a first filtered image, a second filtered image and a third filtered image, respectively, wherein the extreme filtering is a maximum filtering or a minimum filtering;
determining a first difference image and a second difference image according to the first filtered image, the second filtered image and the third filtered image; wherein the first difference image represents a difference in brightness between the first filtered image and the second filtered image, and the second difference image represents a difference in brightness between the second filtered image and the third filtered image;
determining a candidate image according to the first difference image and the second difference image; a point in the candidate image whose corresponding point in the first difference image has a brightness exceeding a first threshold value and whose corresponding point in the second difference image has a brightness exceeding a second threshold value is a valid point, and other points in the candidate image are invalid points; and
determining that at least part of points in the second frame of image corresponding to the valid point in the candidate image are bad points,
wherein the determining a candidate image according to the first difference image and second difference image comprises:
determining a first binarized image according to the first difference image, and determining a second binarized image according to the second difference image; a point in the first binarized image whose corresponding point in the first difference image has a brightness exceeding the first threshold value is a first valid point, and a point in the second binarized image whose corresponding point in the second difference image has a brightness exceeding the second threshold value is a second valid point; and
determining the candidate image according to the first binarized image and the second binarized image; wherein a point in the candidate image whose corresponding point is the first valid point in the first binarized image and whose corresponding point is the second valid point in the second binarized image is a valid point, and other points in the candidate image are invalid points,
before the determining the first binarized image from the first difference image and determining the second binarized image from the second difference image, the method further comprises:
normalizing a brightness of all points in the first difference image into a number greater than or equal to 0 and less than or equal to 1 by taking a brightness of a point in the first difference image with a maximum brightness as 1 and a minimum brightness as 0; normalizing a brightness of all the points in the second difference image into a number greater than or equal to 0 and less than or equal to 1 by taking a brightness of a point in the second difference image with a maximum brightness as 1 and a minimum brightness as 0;
the first threshold value T1 is calculated by following formula: T1=(1−minN1)*factor;
the second threshold value T2 is calculated by following formula: T2=(1−minN2)*factor;
wherein the minN1 is a normalized brightness of the point whose brightness is minimum in the first difference image, the minN2 is a normalized brightness of the point whose brightness is minimum in the second difference image, and the factor is a preset coefficient larger than 0 and smaller than 1.