7. Arithmetic and logic operations

Image arithmetic applies one of the standard arithmetic operations or a logical operator to two or more images. The operators are applied in a pixel-by-pixel way, i.e. the value of a pixel in the output image depends only on the values of the corresponding pixels in the input images. Hence, the images must be of the same size. Although image arithmetic is the most simple form of image processing, there is a wide range of applications. A main advantage of arithmetic operators is that the process is very simple and therefore fast. 

Logical operators are often used to combine two (mostly binary) images. In the case of integer images, the logical operator is normally applied in a bitwise way.

In this lecture we will talk about arithmetic operations such as subtraction and averaging as well as logic operations such as Not, And, and OR. In this lecture we will see how we can remove noise from an image by using image averaging.