Loading existing Ground Truth in Ground Truth Labeler

How do you load an existing Ground Truth into the Ground Truth Labeler App for refinements? The gTruth of our videos gets created either by an algorithm or by hand and I want to change mislabeled or undetected objects by the algorithm in the app.

Using groundTruthLabeler('groundTruthLabel.mat') returns an error that it's not a LabelingSession. You can load Labels from a groundTruth object through 'Import Labels' in the app if I'm correct, but I want to automatize this.

On a sidenote: Where exactly does the Labeler App get the path to the Ground Truth from in the Session object?

Answer 1

[Kritika Bansal]

Hi,

Assuming you are using MATLAB R2019b, the input to groundTruthLabeler can be either a sessionFile or others as mentioned here: https://www.mathworks.com/help/driving/ref/groundtruthlabeler-app.html

The sessionFile will load the saved session that you have saved using the app.

The reason behind the error message you are getting is probably because the argument you are passing is not a proper Session object. If you will load the sessionFile (MAT-File) into your workspace by using the command

load('groundTruthLabelingSession1.mat');

A variable called groundTruthLabelingSession gets loaded into your workspace. To know the path to the ground truth from the session object, you can do

groundTruthLabelingSession

after loading the sessionFile into workspace.

If you have generated the MAT-file using Export labels button, it will save a groundTruth object as MAT-file. You may not be able to directly use this object to launch the app.