The ROBERTS function returns an approximation to the Roberts edge enhancement operator for images: Ga ( j , k ) = Ù F j, k - F j + 1, k + 1 Ù + Ù F j, k + 1 - F j + 1, k Ù
which is a simple, two-dimensional differencing method for edge-sharpening and isolation. The result of this function is a two-dimensional array of integer type, with the same dimensions as Image .
If the variable IM contains a two-dimensional image array, a Roberts sharpened version of IM can be displayed with the command: