### 3.8. Selective Gaussian Blur

#### 3.8.1. Overview

Obrázok 17.27. The Selective Gaussian Blur filter

Original image

Filter applied

Contrary to the other blur plug-ins, the Selective Gaussian Blur plug-in doesn't act on all pixels: blur is applied only if the difference between its value and the value of the surrounding pixels is less than a defined Delta value. So, contrasts are preserved because difference is high on contrast limits. It is used to blur a background so that the foreground subject will stand out better. This add a sense of depth to the image with only a single operation.

#### 3.8.2. Activating the Filter

This filter is found in the main menu under Filters → Blur → Selective Gaussian Blur….

#### 3.8.3. Options

Obrázok 17.28. “Selective Gaussian” filter parameters settings

Presets, “Input Type”, Clipping, Blending Options, Preview, Merge filter, Split view

  | Poznámka
  These options are described in Oddiel 2, “Common Features”.

Aux

  If there is another image on screen, you can select it as auxiliary input.

Blur radius

  Here you can set the blur intensity, in pixels.

Max. delta

  Maximum delta sets the maximum difference (0.0-1.0) between the pixel to be blurred and its surrounding pixels. When the value is above this delta, the blur will not be applied to that pixel.

3.7. Pixelize |  | 3.9. Variable Blur

Report a bug in GIMP Report a documentation error