Imagick::convertFormat

static function convertFormat($format)
{
	static $formats = [
		FileImage::FORMAT_BMP => "bmp",
		FileImage::FORMAT_GIF => "gif",
		FileImage::FORMAT_JPEG => "jpg",
		FileImage::FORMAT_PNG => "png",
		FileImage::FORMAT_WEBP => "webp",
	];

	if(isset($formats[$format]))
	{
		return $formats[$format];
	}
	return null;
}