Only support thresholding method `otsu`

Closes #211 (closed)

dan/ocr/predict/__init__.py

@@ -135,19 +135,6 @@ def add_predict_parser(subcommands) -> None:
         type=int,
         default=None,
     )
-    parser.add_argument(
-        "--threshold-method",
-        help="Thresholding method.",
-        choices=["otsu", "simple"],
-        type=str,
-        default="otsu",
-    )
-    parser.add_argument(
-        "--threshold-value",
-        help="Thresholding value.",
-        type=int,
-        default=0,
-    )
     parser.add_argument(
         "--gpu-device",
         help="Use a specific GPU if available.",