ETG_FocalStatistics

Focal Statistics

Derives value for the output calls from a neighborhood of cells centered in the output cell. The neighborhood is with user defined shape (square or circle) and size (width or diameter) in number of cells.

Neighborhoods:

Square
- Width = 3
- Width = 5
Circle
- Diameter = 3
- Diameter = 5

Inputs:

Input raster dataset
Output raster name and format
Neighborhood shape
- Square
- Circle
Neighborhood size (width for square and diameter for circle) in pixels/number of cells. The size needs to be an odd number in order to place the cell for which the calculations are performed in the center of the neighborhood.
Statistics type.
- Integer and Floating point rasters
  - Sum - the sum of the cell values within the neighborhood
  - Min - the minimum values within the neighborhood
  - Max- the maximum value within the neighborhood
  - Range - the range of values within the neighborhood
  - Mean - the average of the values within the neighborhood
  - STD - the standard deviation of the values in the neighborhood
  - Median - the median value in the neighborhood
- Integer rasters only
  - Majority - the majority value (the value that appears most times in the neighborhood).
  - Minority - the minority value (the value that appears least times in the neighborhood).
  - Variety - variety (the number of unique values in the neighborhood).

Outputs:

A raster with type depending on the type of the input raster and the type of statistics performed.
- Floating point input raster - Floating point output
- Integer input raster
  - MEAN or STD statistics type - Floating point output
  - Any other type statistics - Integer output

Notes:

The input format accepted are file based rasters - ERDAS IMAGINE or Tagged Image File Format (TIFF).
The .NET ToolBox for ArcGIS Desktop accepts also FileGDB Raster inputs.
For file based rasters initially the name of the output raster define the raster format:
- .img extension (for example raster1.img) - ERDAS IMAGINE image.
- .tif extension (for example raster1.tif - image.
- The initial output raster format can be changed by selecting the desired output in the dialog.

Example:

Sum = 49
Min = 2
Max = 9
Range = 7
Mean = 5.44
STD = 2.54
Median = 5
Majority = 3
Minority = 2
Variety = 7

Running Programmatically

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Parameters

Expression	Explanation
Function Name	FocalStatistics
<InputRaster>	A String - full path to the input raster dataset.
<OutputRaster>	A String - full path to the output raster dataset.
<StatisticsType>	A String - the type of the statistics to be calculated. Valid values: Sum Min Max Range Mean STD Median Majority Minority Variety
<NeighborhoodType>	A String - the neighborhood type. Valid values: Square and Circle.
<NeighborhoodSize>	An integer - the side of the square or the diameter of the circle in pixels/number of cells. This should be an odd number.

Running the function

ETSPath used in the table below is the full path to ETSRun.exe (E.G. "C:\Program Files\ETSpatial Techniques\ETSurface\ETSRun.exe")

InputRaster

Language	Syntax
Python	subprocess.call([ETSPath, "FocalStatistics", "InputRaster", "OutputRaster", "InputRaster", "NeighborhoodType", "NeighborhoodSize"])
.NET using ETSRun.exe	StartInfo.FileName = ETSPath StartInfo.Arguments = "FocalStatistics" "InputRaster" "OutputRaster" "InputRaster" "NeighborhoodType" "NeighborhoodSize"
.NET using ETSOutX.dll	FocalStatistics(InputRaster, OutputRaster, InputRaster, NeighborhoodType, NeighborhoodSize)
ArcPy	arcpy.FocalStatistics("InputRaster", "OutputRaster", "InputRaster", "NeighborhoodType", "NeighborhoodSize")

Notes:

<> - required parameter
{} - optional parameter
See examples for Python , .NET or ArcPy
The argument separator for StartInfo.Arguments is space. If a string might contain a space, you need to double quote it.

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