giant.image_processing.VERTICAL_KERNEL

giant.image_processing.VERTICAL_KERNEL = array([[ 1,  2,  1],        [ 0,  0,  0],        [-1, -2, -1]])

The vertical Sobel kernel for convolving with an image when computing the vertical image gradients.

https://www.researchgate.net/publication/239398674_An_Isotropic_3x3_Image_Gradient_Operator