Can you explain the operation in the function rotateImage?

[DRjy]

caps/dataloader/data_utils.py

Line 17 in 3ed2670

scale_h = (h / cos + (w - h * tan) * sin) / h

caps/dataloader/data_utils.py

Line 18 in 3ed2670

scale_w = (h / sin + (w - h / tan) * cos) / w

caps/dataloader/data_utils.py

Line 19 in 3ed2670

scale = max(scale_h, scale_w)

Hi, thanks your great work. I have a trobule in understanding the operation of rotation.
I dont derive the new_height and new_width, and do not understand why the maximum of max(scale_h, scale_w) as the final scale? Can you give me a detailed explanation?

Thank you @qianqianwang68 in advance!