Can someone explain the output of forward() in DNN module?

Question

when I learn YOLO using opencv, and I use 1 class.

outs = net.forward(output_layers)

if I print the output is as follows:

[9.31552518e-03 7.26305973e-03 2.51572542e-02 1.67992767e-02 1.28286320e-06 0.00000000e+00]

I understand that index 0 to index 3 is the coordinates of the box. and the 5th index is the score of each class. But, I'm confused what is the function of the 4th index?

Thank you in advance. I really appreciate it!

Answer 1

Here, index position 1 contains the class label

Index position 2 contains the confidence score. This is not a probability score but rather the model’s confidence for the object belonging to the class that it has detected.

Of the final four values, the first two are x, y bounding box coordinates, and the last is the bounding box’s width and height.