Arithmetic mean filter

Revision as of 15:22, 15 November 2019

Arithmetic mean filter is commonly used for noise reduction. The filter computes the value of each output pixel by finding the statistical mean of the neighborhood of the corresponding input pixel (Fig. A).

Figure A: Principle of arithmetic mean filtering using a rectangular moving window to define a neighborhood

Mean filter using OTB

• In the search engine of the Processing Toolbox, type Smoothing and select Smoothing(mean) under Image Filtering of the Orfeo Toolbox.
• Under the Parameters tab, select a single band or a multiband file as input layer.
• Select mean from the drop-down list as Smoothing Type.
• Adjust the Radius of a circular element in pixel size.

Mean filter using SAGA

• In the search engine of the Processing Toolbox, type Simple filter and select Simple filter under Raster Filter of SAGA.
• Under the Parameters tab, select a single band as Grid.
• Select Circle from the drop-down list as Search Mode.
• Choose Smooth as Filter
• Use the 2 pixels as Radius.

Figure B: Input image: Sentinel-2 composite (RGB=B7,B6,B5) of campus north, University Göttingen

Figure C: Output image: mean filtered Sentinel-2 composite (RGB=B7,B6,B5) of campus north, University Göttingen