diff --git a/src/common_class/frame.h b/src/common_class/frame.h
index d68822e202128cba896f71d764b1c6f66339c92f..936bae3aba6c67c358e33c88d73bd5e27f60f22a 100644
--- a/src/common_class/frame.h
+++ b/src/common_class/frame.h
@@ -48,7 +48,7 @@ public:
 	/**
 	 * \brief Constructor
 	 */
-	Frame(const cv::Mat _img, const int& _id = 0, const KeyPointVector _kps = KeyPointVector(), const cv::Mat _desc = cv::Mat()) :
+	Frame(const cv::Mat& _img, const int& _id = 0, const KeyPointVector _kps = KeyPointVector(), const cv::Mat _desc = cv::Mat()) :
 		id_(_id),
 		img_(_img),
 		kps_(_kps),