Maybe a bug?

[MingtaoFu]

s2anet/mmdet/core/bbox/transforms_rbox.py

Line 350 in 19bb412

angle = (angle + PI / 4) % PI - PI / 4

Should it be angles?

[csuhan]

Thank you for your suggestion! This is indeed a mistake. We will update it later.
poly2rbox_torch is a function in the very early library for rbox-poly-bbox transformation.
Due to the change of data format (xywha for now, other than xyxyxyxy), it has been abandoned.
So, it will not affect the performace of S2ANet (as well as faster rcnn, retinanet).

[Lg955]

s2anet/mmdet/core/bbox/transforms_rbox.py

Line 75 in 19bb412

gx = dx * Rroi_w * torch.cos(Rroi_angle) \

gx = dx * Rroi_w * torch.cos(Rroi_angle) - dy * Rroi_h * torch.sin(Rroi_angle) + Rroi_x
gy = dx * Rroi_w * torch.sin(Rroi_angle) + dy * Rroi_h * torch.cos(Rroi_angle) + Rroi_y
gw = Rroi_w * dw.exp()
gh = Rroi_h * dh.exp()
ga = np.pi * dangle + Rroi_angle

Which formula or figure in the paper corresponds to these formulas?