binary label map layers

Operating system: windows 10
Slicer version: 4.11.20200930
Expected behavior: keep every segment in different layer when saving after annotation
Actual behavior: all segments merged in one layer

Operating system: windows10
Slicer version: 4.11.20200930
Expected behavior: every segment in different layers after saving
Actual behavior: all segments are automatically collapse 1 layer after saving.
how can i solve it?

A few years ago we did not collapse layers and it led to lots of complaints an inefficiencies. Therefore, I would recommend to keep using the collapsed format and use these code snippets to retrieve metadata and pixel data of segments:

If this does not work for you then you can submit a feature request to asking for adding a flag to the storage node that can disable automatic collapsing on save.