Table 4 An overview of the 12 COCO metrics.

AP (Average Precision)

mAP

The average of the AP over 10 IoU thresholds of .50:.05:.95, where AP is the mean aver-age precision over all categories, and IoU is the intersection over union

AP⁵⁰

The AP at the IoU thresholds of .50, this metric is equivalent to the Pascal VOC metric

AP⁷⁵

The AP at the IoU thresholds of .75

AP Across Scales

AP^S

The AP for small objects with bounding box area less than 32² pixels

AP^M

The AP for medium objects with bounding box area between 32² and 96² pixels

AP^L

The AP for large objects with bounding box area greater than 96² pixels

AR (Average Recall)

AR¹

The maximum recall given 1 detection per image, which is averaged over all categories and IoUs

AR¹⁰

The maximum recall given 10 detections per image, which is averaged over all categories and IoUs

AR¹⁰⁰

The maximum recall given 100 detections per image, which is averaged over all categories and IoUs

AR Across Scales

AR^S

The AR for small objects with bounding box area less than 32² pixels

AR^M

The AR for medium objects with bounding box area between 32² and 96² pixels

AR^L

The AR for large objects with bounding box area greater than 96² pixels