Conflicts in evaluation with confidence values and IoU value

[Satishrajc]

Manually Labeled data(Ground Truth): GT 1, GT2
Algorithm Detection: Det1, Det2

Now, IoU threshold : 50% and

• Det1 has a Confidence value 80
• Det1 has IoU wr.t to GT1 60
• Det1 has IoU wr.t to GT2 80 

• Det1 has a Confidence value of 60
• Det2 has IoU w.r.t to GT1 60
• Det2 has IoU w.r.t to GT2 90 

•  In the tool we are going to sort detection according to confidence value and hence will consider Det1 first and then  Det2
• First we take Det1 and compare it with all the GTs in the frame in this case it is GT1 and GT2
• Will compare, Det1 with GT1 and GT2, and since IoU with GT2 is high will take it as TP and flag the GT2
• Next time will take Det2 and will calculation for all the GT  i.e. GT1 and GT2 and 
• Det2 has a higher IoU value for GT2 to hence will consider but GT2 is already flagged hence we IGNORE the Det2

Now, in this case why we are not considering Det2 anywhere?