# Dataset contract

No real dataset is bundled. Verify original download terms before use. Create a CSV:

```csv
id,image,mask,split,group
example_train,images/example_train.png,masks/example_train.png,train,scene_a
example_dev,images/example_dev.png,masks/example_dev.png,dev,scene_b
example_cal,images/example_cal.png,masks/example_cal.png,cal,scene_c
example_test,images/example_test.png,masks/example_test.png,test,scene_d
```

These are format examples, not real files. Paths resolve relative to the CSV. Input is 2D uint8 grayscale, masks are same-sized 2D arrays with zero background and positive foreground. Conversion from 16-bit data requires an explicit versioned preprocessing procedure; the loader refuses silent conversion. Preserve native coordinates. Scene groups must not cross splits. Group fields cannot establish independence by themselves.

Keep dataset source URL, downloaded archive SHA256, actual license text, upstream split hashes, conversion settings and annotation-audit findings beside the private data. Do not redistribute datasets with this repository until rights are established.