3.4.3.11. Neighbor pixels

_images/neighbor_pixels_tab.jpg

neighbor_pixels_tool 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.

3.4.3.11.1. Neighbor pixels

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

  • Neighbor distance in pixels input_number checkbox Circular: if checkbox 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 checkbox 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_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
  • checkbox Create virtual raster output optional: 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 input_text: set the prefix for output file names (default is neighbor);

3.4.3.11.2. Statistic

  • Select a statistic input_list input_text: select a statistic; available options are Sum, Max, Min, Count, Mean, Median, Percentile, StandardDeviation; for Percentile a value can be entered;
  • BATCH batch_tool: add this function to the Batch;
  • RUN run: choose the output destination and start the calculation;