ArrayFilter

ArrayFilter[f, array, r] applies f to all range-r blocks in the specified array.

ArrayFilter[f, array, {r1, r2, ...}] applies f to blocks with ranges r1, r2, ... in successive dimensions.

Examples

Apply a mean filter to an array:

ArrayFilter[Mean, {1, 2, 3, 4, 5}, 1]
(* {3/2, 2, 3, 4, 9/2} *)

2D filtering:

ArrayFilter[Max, {{1, 2}, {3, 4}}, 1]

Please visit the official Wolfram Language Reference for more details.