update from https://github.com/WongKinYiu/yolov7/blob/main/utils/general.py

Author: yixu.cui

utils/general.py

@@ -310,6 +310,7 @@ def segments2boxes(segments):
 def resample_segments(segments, n=1000):
     # Up-sample an (n,2) segment
     for i, s in enumerate(segments):
+        s = np.concatenate((s, s[0:1, :]), axis=0)
         x = np.linspace(0, len(s) - 1, n)
         xp = np.arange(len(s))
         segments[i] = np.concatenate([np.interp(x, xp, s[:, i]) for i in range(2)]).reshape(2, -1).T  # segment xy
@@ -646,7 +647,11 @@ def non_max_suppression(prediction, conf_thres=0.25, iou_thres=0.45, classes=Non
             continue
 
         # Compute conf
-        x[:, 5:] *= x[:, 4:5]  # conf = obj_conf * cls_conf
+        if nc == 1:
+            x[:, 5:] = x[:, 4:5] # for models with one class, cls_loss is 0 and cls_conf is always 0.5,
+                                 # so there is no need to multiplicate.
+        else:
+            x[:, 5:] *= x[:, 4:5]  # conf = obj_conf * cls_conf
 
         # Box (center x, center y, width, height) to (x1, y1, x2, y2)
         box = xywh2xyxy(x[:, :4])