From cfab5b39c010779d03bc2b5ba466ee9ad9ac8424 Mon Sep 17 00:00:00 2001
From: MengzhangLI <mcmong@pku.edu.cn>
Date: Tue, 22 Nov 2022 00:52:36 +0800
Subject: [PATCH] [Fix] Fix ignore class id from -1 to 255 in BaseSegDataset in
 1.x

---
 mmseg/datasets/basesegdataset.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mmseg/datasets/basesegdataset.py b/mmseg/datasets/basesegdataset.py
index 67760841e..e97f8ca9d 100644
--- a/mmseg/datasets/basesegdataset.py
+++ b/mmseg/datasets/basesegdataset.py
@@ -179,7 +179,7 @@ class BaseSegDataset(BaseDataset):
                     f'subset of classes {old_classes} in METAINFO.')
             for i, c in enumerate(old_classes):
                 if c not in new_classes:
-                    label_map[i] = -1
+                    label_map[i] = 255
                 else:
                     label_map[i] = new_classes.index(c)
             return label_map