Neos\Media\Command\MediaCommandController::createThumbnailsCommand PHP Method

    public function createThumbnailsCommand($preset = null, $async = null)
    {
        $async = $async !== null ? $async : $this->asyncThumbnails;
        $presets = $preset !== null ? [$preset] : array_keys($this->thumbnailService->getPresets());
        $presetThumbnailConfigurations = [];
        foreach ($presets as $preset) {
            $presetThumbnailConfigurations[] = $this->thumbnailService->getThumbnailConfigurationForPreset($preset, $async);
        }
        $iterator = $this->assetRepository->findAllIterator();
        $imageCount = $this->assetRepository->countAll();
        $this->output->progressStart($imageCount * count($presetThumbnailConfigurations));
        foreach ($this->assetRepository->iterate($iterator) as $image) {
            foreach ($presetThumbnailConfigurations as $presetThumbnailConfiguration) {
                $this->thumbnailService->getThumbnail($image, $presetThumbnailConfiguration);
                $this->persistenceManager->persistAll();
                $this->output->progressAdvance(1);
            }
        }
    }