Add variable-stride inference support (#2091)

detect.py

@@ -31,7 +31,8 @@ def detect(save_img=False):
 
     # Load model
     model = attempt_load(weights, map_location=device)  # load FP32 model
-    imgsz = check_img_size(imgsz, s=model.stride.max())  # check img_size
+    stride = int(model.stride.max())  # model stride
+    imgsz = check_img_size(imgsz, s=stride)  # check img_size
     if half:
         model.half()  # to FP16
 
@@ -46,10 +47,10 @@ def detect(save_img=False):
     if webcam:
         view_img = True
         cudnn.benchmark = True  # set True to speed up constant image size inference
-        dataset = LoadStreams(source, img_size=imgsz)
+        dataset = LoadStreams(source, img_size=imgsz, stride=stride)
     else:
         save_img = True
-        dataset = LoadImages(source, img_size=imgsz)
+        dataset = LoadImages(source, img_size=imgsz, stride=stride)
 
     # Get names and colors
     names = model.module.names if hasattr(model, 'module') else model.names