gistfile1.php

// $path sollte das Verzeichnis mit den Bildern sein
$images = \TYPO3\Flow\Utility\Files::readDirectoryRecursively($path)

foreach($images as $imageFilePath) {
  $resource = $this->resourceManager->importResource($imageFilePath);
  $image = new \TYPO3\Media\Domain\Model\Image($resource);
  $this->assetRepository->add($image);
  unlink($imageFilePath); 
}