code: public function execute()
      {
          $configuration = ConfigurationController::readConfiguration();
  
          $this->imageResizer = GeneralUtility::makeInstance(\Causal\ImageAutoresize\Service\ImageResizer::class);
          $this->imageResizer->initializeRulesets($configuration);
  
          if (empty($this->directories)) {
              // Process watched directories
              $directories = $this->imageResizer->getAllDirectories();
          } else {
              $directories = GeneralUtility::trimExplode(LF, $this->directories, true);
          }
          $processedDirectories = [];
  
          // Expand watched directories if they contain wildcard characters
          $expandedDirectories = [];
          foreach ($directories as $directory) {
              if (($pos = strpos($directory, '/*')) !== false) {
                  $pattern = $this->imageResizer->getDirectoryPattern($directory);
                  $basePath = substr($directory, 0, $pos + 1);
  
                  $objects = new \RecursiveIteratorIterator(
                      new \RecursiveDirectoryIterator(PATH_site . $basePath),
                      \RecursiveIteratorIterator::SELF_FIRST
                  );
                  foreach ($objects as $name => $object) {
                      $relativePath = substr($name, strlen(PATH_site));
                      if (substr($relativePath, -2) === DIRECTORY_SEPARATOR . '.') {
                          if (preg_match($pattern, $relativePath)) {
                              $expandedDirectories[] = substr($relativePath, 0, -1);
                          }
                      }
                  }
              } else {
                  $expandedDirectories[] = $directory;
              }
          }
          $directories = $expandedDirectories;
  
          $success = true;
          foreach ($directories as $directory) {
              $skip = false;
              foreach ($processedDirectories as $processedDirectory) {
                  if (GeneralUtility::isFirstPartOfStr($directory, $processedDirectory)) {
                      continue 2;
                  }
              }
  
              // Execute bach resize
              $success |= $this->batchResizePictures($directory);
              $processedDirectories[] = $directory;
          }
  
          return $success;
      }
docs: Batch resize pictures, called by scheduler.
  
  @return boolean true if task run was successful