Chapter 17. Filters
| Part III. Function Reference |

## Chapter 17. Filters

## 1. Introduction

A filter is a special kind of tool designed to take an input layer or image, apply a mathematical algorithm to it, and return the input layer or image in a modified format. GIMP uses filters to achieve a variety of effects and those effects are discussed here.

The filters are divided into several categories:

- Section 2, “Blur Filters”

- Section 3, “Enhance Filters”

- Section 4, “Distort Filters”

- Section 5, “Light and Shadow Filters”

- Section 6, “Noise Filters”

- Section 7, “Edge-Detect Filters”

- Section 8, “Generic Filters”

- Section 9, “Combine Filters”

- Section 10, “Artistic Filters”

- Section 11, “Decor Filters”

- Section 12, “Map Filters”

- Section 13, “Rendering Filters”

- Section 14, “Web Filters”

- Section 15, “Animation Filters”

- Section 16, “Alpha to Logo Filters”

### 1.1. Preview

Most filters have a Preview where changes in the image are displayed, in real time (if the “Preview” option is checked), before being applied to the image.

Figure 17.1. Preview submenu

Right clicking on the Preview window opens a submenu which lets you set the Style and the Size of checks representing transparency.

12.8. GIMP online |  | 2. Blur Filters

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