Fix(2d_segmentation): Restore the predicted value of seg image to the range of 0~225 before saving it

[Reqwey]

Description

To fix the problem that evaluation output images are all black because post_trans scale their pixel values to 0~1.

Checks

• Avoid including large-size files in the PR.
• Clean up long text outputs from code cells in the notebook.
• For security purposes, please check the contents and remove any sensitive info such as user names and private key.
• Ensure (1) hyperlinks and markdown anchors are working (2) use relative paths for tutorial repo files (3) put figure and graphs in the ./figure folder
• Notebook runs automatically ./runner.sh -t <path to .ipynb file>