3.3. Despeckle
| 3. Enhance Filters |

### 3.3. Despeckle

#### 3.3.1. Overview

It is used to remove small defects due to dust, or scratches, on a scanned image, and also moiré effect on image scanned from a magazine. You ought to select isolated defects before applying this filter, in order to avoid unwanted changes in other areas of your image.

#### 3.3.2. Activating the filter

You can find this filter through Filters → Enhance → Despeckle.

#### 3.3.3. Options

Figure 16.22. “Despeckle” filter options

Preview

  Parameter setting results are interactively displayed in preview.

Type

  - Adaptive: Adapts radius to image or selection content (using Histogram). If this option is checked, radius slider is not efficient. It renders a result smoother than with radius alone.

  - Recursive: Repeats filter action which gets stronger.

Radius

  Radius: Sets size of action window from 1 (3x3 pixels) to 20 (41x41). This window moves over the image, and the color in it is smoothed, so imperfections are removed.

Black level

  Black level: Removes pixels darker than set value (0-255).

White level

  White level: Removes pixels whiter than set value (0-255).

3.2. Deinterlace |  | 3.4. NL Filter