2.4. Selective Gaussian Blur

2.4. Selective Gaussian Blur
	2. Blur Filters

2.4.1. Overview

Figure 17.11. The Selective Gaussian Blur filter

Original

Blur 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.

2.4.2. Activate the filter

You can find this filter in the image menu under Filters → Blur → Selective Gaussian Blur…

2.4.3. Options

Figure 17.12. “Selective Gaussian” filter parameters settings

Blur radius: Here you can set the blur intensity, in pixels.
Max. delta: Here you can set the maximum difference (0-255) between the pixel value and the surrounding pixel values. Above this Delta, blur will not be applied to that pixel.