In function prep_image

[KaiyueTao]

the code in tutorial is different from here:

github:

img = (letterbox_image(img, (inp_dim, inp_dim)))

in tutorial:

img = cv2.resize(img, (inp_dim, inp_dim))

which will make scaling step a little bit wrong(because no letterbox step, then bbox coordinate scaling should be calculated separately)

Anyway, not a big deal, but it's easy to misunderstand, so just issue here:)