public function extToFormat(string $ext_file): string
    {
        if ($ext_file && !preg_match('/^[a-z0-9_\-]+$/ui', $ext_file)) {
            $ext = $this->c::fileExt($ext_file);
        } else {
            $ext = $ext_file;
        }
        switch (($ext = mb_strtolower($ext))) {
            case 'jpg':
                $format = 'jpeg';
                break;

            case 'png':
                $format = 'png32';
                break;

            default:
                $format = $ext;
        }
        return $format;
    }