User Guide

GNU Image Manipulation Program
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15.2.4 Selective Gaussian Blur
15.2.4.1 Overview
Figure 15.11: The Selective Gaussian Blur filter
(a) Original (b) Blur applied
You can find this filter in the image menu under Filters → Blur → Selective Gaussian Blur
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.
15.2.4.2 Options
Figure 15.12: ‘Selective Gaussian’ filter parateters 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.