Pimcore\Model\Asset\Image::update PHP Method

    protected function update()
    {
        // only do this if the file exists and contains data
        if ($this->getDataChanged() || !$this->getCustomSetting("imageDimensionsCalculated")) {
            try {
                // save the current data into a tmp file to calculate the dimensions, otherwise updates wouldn't be updated
                // because the file is written in parent::update();
                $tmpFile = $this->getTemporaryFile();
                $dimensions = $this->getDimensions($tmpFile, true);
                unlink($tmpFile);
                if ($dimensions && $dimensions["width"]) {
                    $this->setCustomSetting("imageWidth", $dimensions["width"]);
                    $this->setCustomSetting("imageHeight", $dimensions["height"]);
                }
            } catch (\Exception $e) {
                Logger::error("Problem getting the dimensions of the image with ID " . $this->getId());
            }
            // this is to be downward compatible so that the controller can check if the dimensions are already calculated
            // and also to just do the calculation once, because the calculation can fail, an then the controller tries to
            // calculate the dimensions on every request an also will create a version, ...
            $this->setCustomSetting("imageDimensionsCalculated", true);
        }
        parent::update();
        $this->clearThumbnails();
        // now directly create "system" thumbnails (eg. for the tree, ...)
        if ($this->getDataChanged()) {
            try {
                $path = $this->getThumbnail(Image\Thumbnail\Config::getPreviewConfig())->getFileSystemPath();
                // set the modification time of the thumbnail to the same time from the asset
                // so that the thumbnail check doesn't fail in Asset\Image\Thumbnail\Processor::process();
                // we need the @ in front of touch because of some stream wrapper (eg. s3) which don't support touch()
                @touch($path, $this->getModificationDate());
            } catch (\Exception $e) {
                Logger::error("Problem while creating system-thumbnails for image " . $this->getRealFullPath());
                Logger::error($e);
            }
        }
    }