The masks used for this purpose are called space masks. Image processing operations implemented with filtering include smoothing, sharpening, and edge enhancement. Filtering is a proximity operation, where the value of any pixel in the output image is determined by applying an algorithm to the values ​​of pixels in the vicinity of the corresponding input pixel. We will consider both linear and nonlinear filters for image enhancement. Linear Filters Linear filters perform linear operations and have corresponding filters in the frequency domain. Regardless of the type of filter used, the basic approach is to sum the products between the mask coefficients and pixel intensities under the mask at a specific location in the image. Consider a 3x3 mask W_i and the intensities of the pixels under the mask are Z_i. The response R of a linear mask is given by, R= w_1 z_1+w_2 z_2+w_3 z_3+……..+w_9 z_9 (2.9.1) Where, w_1 w_2 w_3 w_4 w_5 w_6 w_7 w_8 w_9 z_1 z_2 z_3 z_4 z_5 z_6 z_7z_8