# Gaussian filter

From AWF-Wiki

The Gaussian smoothing filter is used for noise reduction and removing details. The filter is similar to the arithmetic mean filter but it uses a different kernel that represents the shape of a 2 dimensional Gaussian distribution which is defined as
\(G_{2D}(x,y,\sigma)=\frac{1}{\sqrt{2 \pi \sigma^2}}e^{-\frac{x^2+y^2}{2\sigma^2}}\) where \(\sigma\) determines the *width* of the kernel.

## Gaussian filter using OTB

- In the search engine of the Processing Toolbox, type
**Smoothing**and select**Smoothing**under Image Filtering of the Orfeo Toolbox. - Under the Parameters tab, select a single band or a multiband file as
**Input Image**. - Select
**gaussian**from the drop-down list as**Smoothing Type**. - Adjust the
**Standard deviation**to.`10` - Maximum kernel width is
**128**. - Select
**Output pixel type**float. - Click Run.

## Gaussian filter using SAGA

- In the search engine of the Processing Toolbox, type
**Gaussian**and select**Gaussian filter**under Raster Filter of SAGA. - Under the Parameters tab, select a
**single band file**as Grid. - Select
**Circle**from the drop-down list as Search Mode. - Choose
**1**as Standard deviation - Use the
**3**pixels as Radius.