Allow YOLOv5 execution from arbitrary cwd (#4954)

* Allow YOLOv5 execution from arbitrary `cwd`

* Fix str bugs

detect.py

@@ -19,6 +19,7 @@ FILE = Path(__file__).resolve()
 ROOT = FILE.parents[0]  # YOLOv5 root directory
 if str(ROOT) not in sys.path:
     sys.path.append(str(ROOT))  # add ROOT to PATH
+ROOT = ROOT.relative_to(Path.cwd())  # relative
 
 from models.experimental import attempt_load
 from utils.datasets import LoadImages, LoadStreams
@@ -30,8 +31,8 @@ from utils.torch_utils import load_classifier, select_device, time_sync
 
 
 @torch.no_grad()
-def run(weights='yolov5s.pt',  # model.pt path(s)
-        source='data/images',  # file/dir/URL/glob, 0 for webcam
+def run(weights=ROOT / 'yolov5s.pt',  # model.pt path(s)
+        source=ROOT / 'data/images',  # file/dir/URL/glob, 0 for webcam
         imgsz=640,  # inference size (pixels)
         conf_thres=0.25,  # confidence threshold
         iou_thres=0.45,  # NMS IOU threshold
@@ -47,7 +48,7 @@ def run(weights='yolov5s.pt',  # model.pt path(s)
         augment=False,  # augmented inference
         visualize=False,  # visualize features
         update=False,  # update all models
-        project='runs/detect',  # save results to project/name
+        project=ROOT / 'runs/detect',  # save results to project/name
         name='exp',  # save results to project/name
         exist_ok=False,  # existing project/name ok, do not increment
         line_thickness=3,  # bounding box thickness (pixels)
@@ -55,6 +56,7 @@ def run(weights='yolov5s.pt',  # model.pt path(s)
         hide_conf=False,  # hide confidences
         half=False,  # use FP16 half-precision inference
         ):
+    source = str(source)
     save_img = not nosave and not source.endswith('.txt')  # save inference images
     webcam = source.isnumeric() or source.endswith('.txt') or source.lower().startswith(
         ('rtsp://', 'rtmp://', 'http://', 'https://'))
@@ -254,8 +256,8 @@ def run(weights='yolov5s.pt',  # model.pt path(s)
 
 def parse_opt():
     parser = argparse.ArgumentParser()
-    parser.add_argument('--weights', nargs='+', type=str, default='yolov5s.pt', help='model path(s)')
-    parser.add_argument('--source', type=str, default='data/images', help='file/dir/URL/glob, 0 for webcam')
+    parser.add_argument('--weights', nargs='+', type=str, default=ROOT / 'yolov5s.pt', help='model path(s)')
+    parser.add_argument('--source', type=str, default=ROOT / 'data/images', help='file/dir/URL/glob, 0 for webcam')
     parser.add_argument('--imgsz', '--img', '--img-size', nargs='+', type=int, default=[640], help='inference size h,w')
     parser.add_argument('--conf-thres', type=float, default=0.25, help='confidence threshold')
     parser.add_argument('--iou-thres', type=float, default=0.45, help='NMS IoU threshold')
@@ -271,7 +273,7 @@ def parse_opt():
     parser.add_argument('--augment', action='store_true', help='augmented inference')
     parser.add_argument('--visualize', action='store_true', help='visualize features')
     parser.add_argument('--update', action='store_true', help='update all models')
-    parser.add_argument('--project', default='runs/detect', help='save results to project/name')
+    parser.add_argument('--project', default=ROOT / 'runs/detect', help='save results to project/name')
     parser.add_argument('--name', default='exp', help='save results to project/name')
     parser.add_argument('--exist-ok', action='store_true', help='existing project/name ok, do not increment')
     parser.add_argument('--line-thickness', default=3, type=int, help='bounding box thickness (pixels)')