3.4.8.3. Processing

_images/settings_processing_tab.png

Processing

3.4.8.3.1. System

  • Available RAM (MB) input_number registry_save: set the available RAM (in MB) that is used during the processes in order to improve the SCP performance; this value should be half of the system RAM (e.g. 1024MB if system has 2GB of RAM); in case of errors, set a value lower than 512MB;
  • CPU threads input_number registry_save: set the number of threads available for processing; it is recommended to set a value lower than the maximum number of system threads (e.g. if the system has 4 available threads set value 3);

http://www.youtube.com/watch?v=KDI3ud9L6UY

3.4.8.3.2. Classification process

  • checkbox Play sound when finished registry_save: if checked, play a sound when the classification process is completed;
  • checkbox Use virtual rasters for temp files registry_save: if checked, create virtual rasters for certain temporary files, instead of creating real rasters; it is useful for reducing disk space usage during calculations;
  • checkbox Raster compression registry_save: if checked, a lossless compression (DEFLATE or PACKBITS) is applied to raster outputs in order to save disk space; it is recommended to check this option, however compressed files are sometimes larger than files without compression;
  • checkbox Enable writing verification registry_save: if checked, the output raster is compared to output calculation in order to avoid writing errors; it can slow the process;

3.4.8.3.3. SMTP process notification

  • SMTP server input_text registry_save: the SMTP server to login for sending a notification email when all the SCP processes are finished (a notification is sent also in case of error, but not in case of crash);
  • user input_text registry_save: the SMTP server user;
  • password input_text registry_save: the SMTP server password;
  • Send email of completed process to input_text registry_save: a list of addresses (separated by comma) to send the notification email to;

3.4.8.3.4. External programs

Some SCP tools require external programs to perform the processing.

  • ESA SNAP GPT executable input_text registry_save optional: enter the path to the SNAP gpt executable; usually C:/snap/bin/gpt.exe for Windows, /Applications/snap/bin/gpt for Mac, and /usr/local/snap/bin/gpt for Linux; for the installation of ESA SNAP, please visit this page http://step.esa.int/main/download/snap-download/ ;
  • Python executable path input_text registry_save optional: enter the path to the Python 3 executable (e.g. /usr/local/bin/python3); should be used only in case of issues with multiprocessing;
  • Python modules path input_text registry_save optional: enter the path to Python modules (e.g. /Applications/QGIS.app/Contents/MacOS/lib/python3.8/site-packages); multiple paths can be entered separated by ; ; QGIS should be restarted;
  • GDAL installation directory input_text registry_save optional: enter the path to the GDAL directory containing tools such as gdal_translate and gdalwarp (e.g. /usr/bin); should be used only in case of issues with GDAL processing;

3.4.8.3.5. Temporary directory

  • open_dir registry_save: select a new temporary directory where temporary files are saved during processing; the path to the current temporary directory is displayed; default is a system temporary directory;
  • reset: reset to default temporary directory;