opt.image_weights bug fix (#885)

train.py

@@ -216,7 +216,7 @@ def train(hyp, opt, device, tb_writer=None):
         model.train()
 
         # Update image weights (optional)
-        if opt.img_weights:
+        if opt.image_weights:
             # Generate indices
             if rank in [-1, 0]:
                 cw = model.class_weights.cpu().numpy() * (1 - maps) ** 2  # class weights
@@ -386,7 +386,6 @@ if __name__ == '__main__':
     parser.add_argument('--epochs', type=int, default=300)
     parser.add_argument('--batch-size', type=int, default=16, help='total batch size for all GPUs')
     parser.add_argument('--img-size', nargs='+', type=int, default=[640, 640], help='[train, test] image sizes')
-    parser.add_argument('--img-weights', action='store_true', help='use weighted image selection for training')
     parser.add_argument('--rect', action='store_true', help='rectangular training')
     parser.add_argument('--resume', nargs='?', const=True, default=False, help='resume most recent training')
     parser.add_argument('--nosave', action='store_true', help='only save final checkpoint')
@@ -395,6 +394,7 @@ if __name__ == '__main__':
     parser.add_argument('--evolve', action='store_true', help='evolve hyperparameters')
     parser.add_argument('--bucket', type=str, default='', help='gsutil bucket')
     parser.add_argument('--cache-images', action='store_true', help='cache images for faster training')
+    parser.add_argument('--image-weights', action='store_true', help='use weighted image selection for training')
     parser.add_argument('--name', default='', help='renames results.txt to results_name.txt if supplied')
     parser.add_argument('--device', default='', help='cuda device, i.e. 0 or 0,1,2,3 or cpu')
     parser.add_argument('--multi-scale', action='store_true', help='vary img-size +/- 50%%')