[scribus] Radius within Image effects

[Gregory Pittman]

Vanessa Callebaut wrote:
> When you apply the effects "Blur" and "Sharpen" to an image, you can select
> a certain "Radius", could somebody please give me some more information on
> what this setting actually does? I can see the difference when changing this
> setting but can not explain it.
>   
Here is an article that explains something about what a program is doing 
when it creates blur:
http://www.codeproject.com/KB/GDI-plus/GausianBlur.aspx

What is happening to the image is that sharp transitions from one color 
to another are reduced. You can do this directionally, but typically 
programs will adjust individual pixels radially around a pixel (data 
points, really). You adjust this radial distance to create more or less 
blur. There are simple and more complex ways of calculating these changes.

In the end, the user is simply looking for a desired effect and not 
exactly worrying about the underlying mathematics.

Greg