AutoShape integer image-size fix (#10090)

Update common.py

We have a division at line 694, and then a multiplication at line 695, so it makes `y*g` not an integer. And since `shape1` will be used at line 697 to ensure the size is divisible by the `stride`, this may lead to different image size.

In my experiment, my image is [640, 640], it's divisible by the default stride 32, but I found that the result is changed to [672, 672] after line 697. So the final detection result is slightly different from that directly using the `detect.py` script, which does not call the AutoShape methods. 


Signed-off-by: janus-zheng <[email protected]>

Signed-off-by: janus-zheng <[email protected]>
Co-authored-by: Glenn Jocher <[email protected]>

models/common.py

@@ -692,7 +692,7 @@ def forward(self, ims, size=640, augment=False, profile=False):
                 s = im.shape[:2]  # HWC
                 shape0.append(s)  # image shape
                 g = max(size) / max(s)  # gain
-                shape1.append([y * g for y in s])
+                shape1.append([int(y * g) for y in s])
                 ims[i] = im if im.data.contiguous else np.ascontiguousarray(im)  # update
             shape1 = [make_divisible(x, self.stride) for x in np.array(shape1).max(0)] if self.pt else size  # inf shape
             x = [letterbox(im, shape1, auto=False)[0] for im in ims]  # pad