vision.labeler.loading.RosbagSource Class

Namespace: vision.labeler.loading
Superclasses: vision.labeler.loading.MultiSignalSource

Load signals from rosbag sources into Ground Truth Labeler app

Description

The vision.labeler.loading.RosbagSource class creates an interface for loading signals from rosbag files into the Ground Truth Labeler app. In the Add/Remove Signal dialog box of the app, when Source Type is set to Rosbag, this class controls the parameters in that dialog box.

To access this dialog box, in the app, select Import > Add Signals.

The default implementation of this class loads signals from these ROS message types:

• sensor_msgs/Image

• sensor_msgs/CompressedImage

• sensor_msgs/PointCloud2

Note

This class requires ROS Toolbox.

The vision.labeler.loading.RosbagSource class is a handle class.

Creation

When you export labels from a Ground Truth Labeler app session that contains rosbag sources, the exported groundTruthMultisignal object stores instances of this class in its DataSource property.

To create a RosbagSource object programmatically, such as when programmatically creating a groundTruthMultisignal object, use the vision.labeler.loading.RosbagSource function (described here).

Syntax

rosbagSource = vision.labeler.loading.RosbagSource

Description

rosbagSource = vision.labeler.loading.RosbagSource creates a RosbagSource object for loading signals from rosbag data sources. To specify the data source and the parameters required to load the source, use the loadSource method.

Properties

Name — Name of source type

"Rosbag" (default) | string scalar

Name of the type of source that this class loads, specified as a string scalar.

Attributes:

GetAccess	public
Constant	true
NonCopyable	true

Description — Description of class functionality

"A rosbag reader" (default) | string scalar

Description of the functionality that this class provides, specified as a string scalar.

Attributes:

GetAccess	public
Constant	true
NonCopyable	true

SourceName — Name of data source

[] (default) | string scalar

Name of the data source, specified as a string scalar. Typically, SourceName is the name of the file from which the signal is loaded.

Attributes:

GetAccess	public
SetAccess	protected

SourceParams — Parameters for loading signals from rosbag data source

[] (default) | empty structure

Parameters for loading signals from a rosbag data source, specified as an empty structure. When you load image or lidar signals from a rosbag, do not specify the signal timestamps or any other parameters. The loadSource method reads these parameters from the rosbag.

Attributes:

GetAccess	public
SetAccess	protected

SignalName — Names of signals in data source

[] (default) | string vector

Names of the signals that can be loaded from the data source, specified as a string vector.

Attributes:

GetAccess	public
SetAccess	protected

SignalType — Types of signals in data source

[] (default) | vector of vision.labeler.loading.SignalType enumerations

Types of the signals that can be loaded from the data source, specified as a vector of vision.labeler.loading.SignalType enumerations. Each signal listed in the SignalName property is of the type in the corresponding position of SignalType.

Attributes:

GetAccess	public
SetAccess	protected

Timestamp — Timestamps of signals in data source

[] (default) | cell array of duration vectors

Timestamps of the signals that can be loaded from the data source, specified as a cell array of duration vectors. Each signal listed in the SignalName property has the timestamps in the corresponding position of Timestamp.

Attributes:

GetAccess	public
SetAccess	protected

NumSignals — Number of signals in data source

0 (default) | integer

Number of signals that can be read from the data source, specified as a nonnegative integer. NumSignals is equal to the number of signals in the SignalName property.

Attributes:

GetAccess	public
SetAccess	public
Dependent	true
NonCopyable	true

Methods

Public Methods

customizeLoadPanel	customizeLoadPanel(sourceObj,panel) Customize the loading panel for the data source object. In the loading dialog box of the app, this method is invoked when you select the data source type from the Source Type list.
getLoadPanelData	[sourceName,sourceParams] = getLoadPanelData(sourceObj) Obtain the data needed to load the data source object currently selected in the loading panel. In the loading dialog box of the app, this method is invoked when you add a source. The method returns these outputs. sourceName is a string capturing the name of the data source object. sourceParams is a structure with fields containing the parameters required to load the data source object. Both of these outputs are passed to the loadSource method.
loadSource	loadSource(sourceObj,sourceName,sourceParams) Load a data source object into the app. In the loading dialog box of the app, this method is invoked after you add a source and the getLoadPanelData method executes successfully. This method is also invoked when you load the data source object into the MATLAB® workspace. When you load the data source object, MATLAB expects that the source has the name sourceName and parameters sourceParams that are needed to load that source and read data from it.
readFrame	frame = readFrame(sourceObj,signalName,tsIndex) Read a frame of data from a signal contained in a data source object at the specified timestamp index. The index must be in the bounds of the length of the timestamps for that signal.
loadPanelChecker	loadPanelChecker Check the load panel for the loading dialog box of the app. This method opens a dialog box similar to the loading dialog box that you open from the Open menu on the app toolstrip. Use this method to preview how the customizeLoadPanel method populates the loading panel for the selected data source object. Static true

Tips

• You can this class as a starting point for creating a custom data source loading class. To view the source code for this class, use this command:

  edit vision.labeler.loading.RosbagSource

Version History

Introduced in R2020a