my own datasets for semantic segmentation

[dawang-11]

Hello Author, I successfully replicated the semantic segmentation task on the cityscapes dataset, but the following error occurred when I tried to replicate it on my own dataset. Let me describe my operation in detail first.
1、register my dateset
2、I added my own dataset's config based on the cityscapes dataset semantic segmentation config.
3、When running the code, the following error occurs

4、The following error occurred when converting the rgb ground truth to a grayscale image and running it again.