Hi Jesus Garcia,
The error you're encountering is due to a mismatch between the type of ground truth object you are passing to the “pixelLabelDatastore” function and what it expects. The “pixelLabelDatastore” requires input in the form of a “groundTruth” object typically exported from the “Image Labeler” or “Video Labeler” apps.
In your case, it seems that the “gTruth” object was generated using the Lidar Labeler app, which creates a “groundTruthLidar” object.
For more information you can refer to the below documentation link on “groundTruth”:
