Online calculator: Box filters for image processing
https://planetcalc.com/9313The online calculator below allows you to apply a box filter to an image. To do this, the handbook Box filters introduces several well-known filters: for sharpening, edge detection, blurring, anti-aliasing or smoothing, embossing, and gaussian blurring. You can immediately apply them to the image and see the result.
Finding the kernel and image
www.math.lsa.umich.edu/~hochster/419/ker.im.htmlFINDING A BASIS FOR THE KERNEL OR IMAGE. To find the kernel of a matrix A is the same as to solve the system AX = 0, and one usually does this by putting A in rref. The matrix A and its rref B have exactly the same kernel. In both cases, the kernel is the set of solutions of the corresponding homogeneous linear equations, AX = 0 or BX = 0.