1only batches of spatial targets supported (non-empty 3D tensors) but got targets of size: : [1, 3, 375, 1242]

Thank you for your explanation, I’m using the KITTI semantic segmentation datasets. which are conform with The Cityscapes Dataset, it has 30 classes. But I didn’t find the key value pair between my colour codes and the corresponding class index.
I have seen the post you mentioned, and I don’t know the class mapping value neither, could you help?