Images can be flagged for testing using context menu in Images list and the Flag images as test command:



Selected images will be assigned a test flag which is reflected by their green color:



TIP: The Ctrl+T keyboard shortcut performs the same action.


Note that the state of the selected images changes by applying this command. Therefore, images that were already part of the test set will become part of the training set.

Additional image flagging commands

The Data menu contains several additional commands for image flagging in Image flags sub-menu:



  • Selected images should all be flagged for training or for testing.
  • A percentage of the selected images can be randomly assigned a test flag. This is useful to perform manual cross-validation on a large number of scans. We select all scans (Ctrl+A) and flag a random fraction as test. We then rebuild a model and record the test set performance. Note that in order to retrain a model, we need to have labeled data. Therefore, most of your scans should be meaningfully annotated in order to use this manual cross-validation approach.