A Computational Introduction to Digital Image Processing, 2nd Edition

Chapter 5

Neighborhood Processing

5.1 Introduction

We have seen in Chapter 4 that an image can be modified by applying a particular function

to each pixel value. Neighborhood processing may be considered an extension of this, where

a function is applied to a neighborhood of each pixel.

The idea is to move a “mask”: a rectangle (usually with sides of odd length) or other

shape over the given image. As we do this, we create a new image whose pixels have

gray values calculated from the gray values under the mask, as shown in Figure 5.1. The

Mask

Pixel at position (x, y)

(a) Original image

Pixel at position (x, y)

(b) Image after filtering

FIGURE 5.1: Using a