Object detection

Object detection has applications in many areas of computer vision, including image retrieval and video surveillance.

[10] Among other uses, cross-domain object detection is applied in autonomous driving, where models can be trained on a vast amount of video game scenes, since the labels can be generated without manual labor.

For example, if there is a traffic sign in the image, with a bounding box drawn by a human ("ground truth label"), then a neural network has detected the traffic sign (a true positive) at 0.5 threshold iff it has drawn a bounding box whose IoU with the ground truth is above 0.5.

For simultaneous object localization and classification, a true positive is one where the class label is correct, and the bounding box has an IoU exceeding the threshold.

The average precision (AP) of the network for a class of objects is the area under the precision-recall curve as the IoU threshold is varied.