Why pos_equal_one , neg_pos_one's dimension is (batch_size, w, l, 2)??

[jinzhongxiao]

Why pos_equal_one , neg_pos_one's dimension is (batch_size, w, l, 2)?? I don't know why last dimension is 2. if it is a positive anchor, we set 1, otherwise we set 0. so (batch_size, w, l, 1) satisfies the condition.

[hm2092]

From my understanding, 2 is the number of anchors per position. One of them is oriented at 0 and other one at pi/2. w and l are the dimensions of probability score map and at each grid, there should be 2 anchor boxes.