Sulu\Bundle\MediaBundle\Media\ImageConverter\ImagineImageConverter::getImageExtension PHP Method

    private function getImageExtension($fileName)
    {
        $pathInfo = pathinfo($fileName);
        $extension = null;
        if (isset($pathInfo['extension'])) {
            $extension = $pathInfo['extension'];
        }
        switch ($extension) {
            case 'png':
            case 'gif':
            case 'jpeg':
                // do nothing
                break;
            case 'svg':
                $extension = 'png';
                break;
            default:
                $extension = 'jpg';
                break;
        }
        return $extension;
    }