Abstract: The present application discloses a shadow detection method and system for monitoring video images, and a shadow removal method. The shadow detection method includes: acquiring a current frame and a background frame from source data; acquiring, from the current frame, first candidate shadow areas; computing a local-ternary-pattern shadow detection value of the first candidate shadow areas, and selecting second candidate shadow areas; computing a hue detection value, a saturation detection value and a gradient detection value of the second candidate shadow areas; estimating a local-ternary-pattern shadow threshold, a hue threshold, a saturation threshold and a gradient threshold; computing a local-ternary-pattern shadow detection value, a hue detection value, a saturation detection value and a gradient detection value of the first candidate shadow areas; and selecting first candidate shadow areas.

Abstract: A face blurring method comprises: acquiring a face image to be processed; aligning the face image onto a face mask, and performing grid division on the same; matching each grid of the divided face image with a grid of a first grid dictionary, obtaining blurred grids corresponding to each grid of the face image, the first grid dictionary obtained by dividing a first two-dimensional image library according to the face mask after alignment; according to the blurred grids, querying in a second grid dictionary a plurality of clear grids corresponding to the blurred grids on a one to one basis, the second grid dictionary obtained after dividing a second two-dimensional image library according to the face mask alignment, and the blurred images correspond to the clear images on a one to one basis; and according to the queried clear grids, generating a clear image of the face image.