Segformer evaluation metrics

[MariaMel98]

When fine tuning a segformer model with a custom dataset we get a table after each validation interval which reports the per class IoU and Acc.
How can I find out how are these metrics calculated exactly? Are they calculated per pixel or in some other way?
Thanks in advance!

[ternsteven]

我个人的理解是按照像素计算的，即计算预测值与真实值的交并比。
公式如下