Error using boxlabeldatastore with Image Labeler dataset

Hello,

I am having an issue with the boxlabeldatastore function when trying to train a YOLO network. I have working Arduino code that allows for bluetooth control of a Pololu Romi and the Matlab script for controlling the robot. The problem is, when trying to train the network on a dataset I created from the Image Labeler tool, I get the following errors:

Error using boxLabelDatastore (line 216)

Incorrect bounding box format. Bounding box must be an M-by-4 numeric matrix, where M specifies the number of boxes in a row. The column in the training data table that contains the

bounding boxes must be a cell array.

Error in TrainingExample_Multi_Class (line 24)

bldsTrain = boxLabelDatastore(trainingDataTbl(:,2:end));

Caused by:

Error using boxLabelDatastore

Expected input number 1, boxes in the training data table, to be one of these types:

double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64

Instead its type was struct.

I've attached both the dataset and training script, but am not sure where to go from here. Please advise.

Answer 1

[Rajani Mishra]

I tried reproducing the problem using the script and mat file provided but I wasn’t able to run the script as the “data.gTruth.DataSource” in the mat file provided by you has paths pointing to locations on your system so it’s producing error while I try to run on my system.

I ran your script using the mat file present in this link’s first example : https://www.mathworks.com/help/vision/ref/boxlabeldatastore.html.

% This data was used
data = load('vehicleTrainingData.mat');
trainingData = data.vehicleTrainingData;

No error is encountered while using boxLableDatastore() function.

After looking into your “data.gTruth”

% line number 4 in your script
data = load('HandLabelDefinitions.mat');

“data.gTruth.DataSource” is of type cell whereas for using function objectDetectorTrainingDat()

% line number 6 in your script
trainingData = objectDetectorTrainingData(data.gTruth);

the groundTruth object should have DataDource property of type groundTruthDataSource object.

You can see "data.gTruth.DataSource" having cell type for your mat file below :

Where as for "vehicleTrainingData.mat" it's of type groundTruthDataSource object :

So convert data.gTruth.DataSource from cell type to the required object type.

Refer to this link for more information : https://www.mathworks.com/help/vision/ref/groundtruth.html