3.4.5.6. Classification sieve

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classification_sieve Classification sieve

This tab allows for the replacement of isolated pixel values with the value of the largest neighbour patch (based on GDAL Sieve ). It is useful for removing small patches from a classification.

3.4.5.6.1. Classification sieve

  • Select the classification input_list: select a raster (already loaded in QGIS);
  • reload: refresh layer list;
  • Size threshold input_number: size of the patch to be replaced (in pixel unit); all patches smaller than the selected number of pixels will be replaced by the value of the largest neighbour patch;
  • Pixel connection input_list: select the type of pixel connection:
    • 4: in a 3x3 window, diagonal pixels are not considered connected;
    • 8: in a 3x3 window, diagonal pixels are considered connected;
  • BATCH batch_tool: add this function to the Batch;
  • RUN run: choose the output destination and start the calculation;