Changes of AP values of different algorithm elements (own creation). Note: The accuracy of various targets of SRSMFF algorithm is greatly improved compared with SRS algorithm. Among them, the accuracy value of wall is increased by 8.18%, that of ordinary door is increased by 4.68%, that of ordinary window is increased by 5.38%, and that of door corner points is increased by 8.27%. The reason for the relatively small improvement of other structural elements is that they are small in the data set and have outstanding features, and the original algorithm has achieved high recognition accuracy.