PhpOffice\PhpPresentation\Writer\PowerPoint2007\DocPropsThumbnail::render PHP Method

    public function render()
    {
        $pathThumbnail = $this->getPresentation()->getPresentationProperties()->getThumbnailPath();
        if ($pathThumbnail) {
            $fileThumbnail = file_get_contents($pathThumbnail);
            $gdImage = imagecreatefromstring($fileThumbnail);
            if ($gdImage) {
                ob_start();
                imagejpeg($gdImage);
                $imageContents = ob_get_contents();
                ob_end_clean();
                imagedestroy($gdImage);
                $this->getZip()->addFromString('docProps/thumbnail.jpeg', $imageContents);
            }
        }
        // Return
        return $this->getZip();
    }