Image Processing

3Image Enhancement

Image enhancement is a group of image techniques used to improve the visual quality of images. These techniques may include pixel operations and mask operations, both of which can be linear or nonlinear. The techniques can be performed either in the image domain or in the frequency domain.

The sections of this chapter are arranged as follows:

Section 3.1 introduces some operations between images, including arithmetic operation and logic operation, and gives some examples of arithmetic operation in image enhancement.

Section 3.2 describes the principle of gray-level mapping, and some typical gray-level mapping functions and their image enhancement effects are also provided.

Section 3.3 focuses on the methods for histogram ...