FluidTYPO3\Vhs\ViewHelpers\Media\Image\AbstractImageViewHelper::preprocessImage PHP Method

    public function preprocessImage($imageSource = null)
    {
        $src = null === $imageSource ? $this->arguments['src'] : $imageSource;
        $width = $this->arguments['width'];
        $height = $this->arguments['height'];
        $minW = $this->arguments['minW'];
        $minH = $this->arguments['minH'];
        $maxW = $this->arguments['maxW'];
        $maxH = $this->arguments['maxH'];
        $format = $this->arguments['format'];
        $quality = $this->arguments['quality'];
        $treatIdAsReference = (bool) $this->arguments['treatIdAsReference'];
        $crop = $this->arguments['crop'];
        if (is_object($src) && $src instanceof FileReference) {
            $src = $src->getUid();
            $treatIdAsReference = true;
        }
        if ($crop === null) {
            $crop = is_object($src) && $src instanceof FileReference ? $src->getProperty('crop') : null;
        }
        if ('BE' === TYPO3_MODE) {
            $this->simulateFrontendEnvironment();
        }
        $setup = ['width' => $width, 'height' => $height, 'minW' => $minW, 'minH' => $minH, 'maxW' => $maxW, 'maxH' => $maxH, 'treatIdAsReference' => $treatIdAsReference, 'crop' => $crop];
        if (false === empty($format)) {
            $setup['ext'] = $format;
        }
        if (0 < (int) $quality) {
            $quality = MathUtility::forceIntegerInRange($quality, 10, 100, 75);
            $setup['params'] = '-quality ' . $quality;
        }
        if (TYPO3_MODE === 'BE' && strpos($src, '../') === 0) {
            $src = substr($src, 3);
        }
        $this->imageInfo = $this->contentObject->getImgResource($src, $setup);
        $GLOBALS['TSFE']->lastImageInfo = $this->imageInfo;
        if (false === is_array($this->imageInfo)) {
            throw new Exception('Could not get image resource for "' . htmlspecialchars($src) . '".', 1253191060);
        }
        if ($this->hasArgument('canvasWidth') && $this->hasArgument('canvasHeight')) {
            $canvasWidth = (int) $this->arguments['canvasWidth'];
            $canvasHeight = (int) $this->arguments['canvasHeight'];
            $canvasColor = str_replace('#', '', $this->arguments['canvasColor']);
            $originalFilename = $this->imageInfo[3];
            $originalExtension = substr($originalFilename, -3);
            $destinationFilename = 'typo3temp/vhs-canvas-' . md5($originalFilename . $canvasColor . $canvasWidth . $canvasHeight) . '.' . $originalExtension;
            $destinationFilepath = GeneralUtility::getFileAbsFileName($destinationFilename);
            if (!file_exists($destinationFilepath)) {
                $arguments = sprintf('%s -background \'#%s\' -gravity center -extent %dx%d %s', $originalFilename, $canvasColor, $canvasWidth, $canvasHeight, $destinationFilepath);
                $command = CommandUtility::imageMagickCommand('convert', $arguments);
                CommandUtility::exec($command);
            }
            $this->imageInfo[3] = $destinationFilename;
        }
        $GLOBALS['TSFE']->imagesOnPage[] = $this->imageInfo[3];
        $GLOBALS['TSFE']->imagesOnPage[] = $this->imageInfo[3];
        $publicUrl = rawurldecode($this->imageInfo[3]);
        $this->mediaSource = GeneralUtility::rawUrlEncodeFP($publicUrl);
        if (TYPO3_MODE === 'BE') {
            $this->resetFrontendEnvironment();
        }
    }