Table 1.

The anchor box size and the corresponding output feature map after K-means clustering.

Size	13 × 13	26 × 26	52 × 52
Anchor box	(171 × 142), (168 × 114), (257 × 283)	(86 × 145), (105 × 70), (122 × 106)	(46 × 50), (72 × 93), (80 × 49)
Receptive field	Big	Middle	Small