You can export the labeled ground truth to a MAT-file or to a variable in the MATLAB workspace. In both cases, the labeled ground truth is stored as a groundTruth object.

You can use the groundTruth object to train a deep-learning-based computer vision algorithm. For more details, see Training Data for Object Detection and Semantic Segmentation.

Note

If you export pixel data, the pixel label data and ground truth data are saved in separate files but in the same folder. For considerations when working with exported pixel labels, see How Labeler Apps Store Exported Pixel Labels.

In this example, you export the labeled ground truth to the MATLAB workspace. From the app toolstrip, select Export Labels > To Workspace. The exported MATLAB variable is gTruth.

Display the properties of the exported groundTruth object. The information in your exported object might differ from the information shown here.

DataSource is a groundTruthDataSource object containing the path to the images or video and timestamps. Display the properties of this object.

LabelDefinitions is a table containing information about the label definitions. This table does not contain information about the labels that are drawn on the video frames. To save the label definitions in their own MAT-file, from the app toolstrip, select Save > Label Definitions. You can then import these label definitions into another app session by selecting Import Files.

Display the label definitions table. Each row contains information about an ROI label definition or a scene label definition. If you exported pixel label data, the LabelDefinitions table also includes a PixelLabelID column containing the ID numbers for each pixel label definition.

Within LabelDefinitions, the Hierarchy column stores information about the sublabel and attribute definitions of a parent ROI label.

Display the sublabel and attribute information for the Car label.

Display information about the headlight sublabel.

Display information about the carType attribute.

Sessions are saved in each step of a team-based project. For more information about each of these steps, see Get Started with Team-Based Labeling.

From the app toolstrip, select Save Project then Save asto save a MAT-file of the app session. The saved session includes the data source, label definitions, and labeled ground truth. It also includes your session preferences, such as the layout of the app. To change layout options, select Layout.

At any time during a session, you can select New Session to start a new session. You have the option of saving the current session or cancelling.

The app session MAT-file is separate from the ground truth MAT-file that is exported when you select Export. To share labeled ground truth data, as a best practice, share the ground truth MAT-file containing the groundTruth object, not the app session MAT-file. For more details, see Share and Store Labeled Ground Truth Data.