[Question] Calculation about shortest_edge

[JJJYmmm]

Question

In llava/conversation.py, to limit image's size, shortest_edge is determined by int(min(max_len / aspect_ratio, min_len, min_hw))

LLaVA/llava/conversation.py

Lines 133 to 143 in 4e2277a

	if max(image.size) > max_len:
	max_hw, min_hw = max(image.size), min(image.size)
	aspect_ratio = max_hw / min_hw
	shortest_edge = int(min(max_len / aspect_ratio, min_len, min_hw))
	longest_edge = int(shortest_edge * aspect_ratio)
	W, H = image.size
	if H > W:
	H, W = longest_edge, shortest_edge
	else:
	H, W = shortest_edge, longest_edge
	image = image.resize((W, H))

① If max(image.size) > max_len, max_len / aspect_ratio is always smaller than min_hw, so shortest_edge can be simplified to int(min(max_len / aspect_ratio, min_len)

max(image.size) > max_len ⇒ max_hw > max_len ⇒ max_hw / min_hw > max_len / min_hw ⇒ min_hw >max_len / aspect_ratio

② I'm also confused about min_len, in int(min(max_len / aspect_ratio, min_len), the constraint about max_len is larger than min_len(the shortest_edge can be smaller than min_len). The only thing min_len does is to resize image smaller when max_len / aspect_ratio > min_len

I think shortest_edge = int(max_len / aspect_ratio) is ok.