4.4.11. Neighbor pixels

Neighbor pixels

This tool allows for the calculation of several neighbor pixels statistics for every band of a band set defined in the Band set.

The statistics are calculated for every pixel of the input raster considering the values of the neighbor pixels. Neighbor pixels are defined through a distance or through a custom matrix.

For example, the following matrix represents the neighbor pixels within a distance of 1 pixel from a central pixel, resulting in a 3x3 matrix.

Neighbor	Neighbor	Neighbor
Neighbor	Center	Neighbor
Neighbor	Neighbor	Neighbor

Several statistics are available. The statistic Sum will result in a raster convolution. For instance, this can be useful to apply an image filter to all the bands a band set for photointerpretation.

An output band is created for every band in the band sets.

4.4.11.1. Neighbor pixels

• Select input band set : select the input Band set;

• Neighbor distance in pixels Circular: if Circular is not checked, use a square matrix centred in one pixel considering all the neighbor pixels within this distance; e.g. a value of 1 results in a 3x3 matrix with weight 1 in every cell; a value of 2 results in a 5x5 matrix with weight 1 in every cell, such as:

  1	1	1	1	1
  1	1	1	1	1
  1	1	1	1	1
  1	1	1	1	1
  1	1	1	1	1

  if Circular is checked, only the cells of the matrix within the radius of distance have value 1, such as:

  0	0	1	0	0
  0	1	1	1	0
  1	1	1	1	1
  0	1	1	1	0
  0	0	1	0	0

• Matrix file (optional) : open a text file (.txt or .csv) containing a matrix structure; the text file must be a list of numbers separated by commas, representing the columns, and each line represents a row of the matrix; nan can be entered for NoData values that will be excluded from the calculation; following an example of matrix file:

  nan,1,nan
  1,1,1
  nan,1,nan
  

Resulting in the following matrix:

NoData	1	NoData
1	1	1
NoData	1	NoData

• Create virtual raster output : if checked, output is created as virtual raster .vrt composed of as many .tif files as the number of CPU threads defined in System; for large rasters this can speed up the process;

• Output name prefix : set the prefix for output file names (default is neighbor);

4.4.11.2. Statistic

• Select a statistic : select a statistic; available options are Sum, Max, Min, Count, Mean, Median, Percentile, StandardDeviation; for Percentile a value can be entered;

• BATCH : add this function to the Batch;

• RUN : choose the output destination and start the calculation;