Choose an App to Label Ground Truth Data

You can use Computer Vision Toolbox™, Automated Driving Toolbox™, Lidar Toolbox™, Audio Toolbox™, Signal Processing Toolbox™, and Medical Imaging Toolbox™ apps to label ground truth data. Use this labeled data to validate or train algorithms such as image classifiers, object detectors, semantic segmentation networks, instance segmentation networks, and deep learning applications. The choice of labeling app depends on several factors, including the supported data sources, labels, and types of automation.

One key consideration is the type of data that you want to label.

• If your data is an image collection, use the Image Labeler app. An image collection is an unordered set of images that can vary in size. For example, you can use the app to label images of books for training a classifier. The Image Labeler can also handle very large images (at least one dimension >8K).

• If your data is a single video or image sequence, use the Video Labeler app. An image sequence is an ordered set of images that resembles a video. For example, you can use this app to label a video or image sequence of cars driving on a highway for training an object detector.

• If your data includes multiple time-overlapped signals, such as videos, image sequences, or lidar signals, use the Ground Truth Labeler (Automated Driving Toolbox) app. For example, you can label data for a single scene captured by multiple sensors mounted on a vehicle.

• If your data is only a lidar signal, use the Lidar Labeler (Lidar Toolbox). For example, you can use this app to label data captured from a point cloud sensor.

• If your data consists of single-channel or multichannel one-dimensional signals, use the Signal Labeler (Signal Processing Toolbox). For example, you can label biomedical, speech, communications, or vibration data. You can also use Signal Labeler to perform audio-specific tasks, such as speech detection and speech-to-text transcription.

• If your data is a 2-D medical image or image series, or a 3-D medical image volume, use the Medical Image Labeler (Medical Imaging Toolbox). For example, you can label computed tomography (CT) image volumes of the chest to train a semantic segmentation network.

This table summarizes the key features of the labeling apps.

Labeling App	Data Sources	Label Support	Automation	Additional Features
Image Labeler	Image collections Very large images (at least one dimension >8K)	Rectangle regions of interest (ROIs) Projected cuboid (ROIs) Line ROIs Pixel ROIs Polygon ROIs Sublabels Attributes Scenes	Built-in automation algorithms Custom automation algorithms Blocked image automation algorithms	View visual summary of labeled data
Video Labeler	Videos Image sequences Custom image data sources	Rectangle ROIs Projected cuboid (ROIs) Line ROIs Pixel ROIs Polygon ROIs Sublabels Attributes Scenes	Built-in automation algorithms Custom automation algorithms Temporal automation algorithms	View visual summary of labeled data
Ground Truth Labeler (Automated Driving Toolbox)	Videos Image sequences Custom image data sources Point cloud sequences (PCD or PLY files) Velodyne® lidar files Rosbags (requires ROS Toolbox)	Rectangle ROIs Projected cuboid (ROIs) Cuboid ROIs Line ROIs Pixel ROIs Polygon ROIs Sublabels Attributes Scenes	Built-in automation algorithms, including vehicle and lane detection algorithms and a point cloud temporal interpolation algorithm Custom automation algorithms Temporal automation algorithms Multisignal automation	View visual summary of labeled data Connect external tool to app for displaying time-synchronized signals, such as lidar or CAN bus data Customize loading interface to support additional data sources
Lidar Labeler (Lidar Toolbox)	Point cloud sequences (PCD or PLY files) Velodyne lidar files LAS/LAZ file sequences Rosbags (requires ROS Toolbox)	Cuboid ROIs Attributes Scenes	Built-in automation algorithms, including a lidar object tracker and point cloud temporal interpolator Custom automation algorithms Temporal automation algorithms	View the cuboid labels in top, side, and front views Save and reuse custom camera views Connect to external tool to display time-synchronized signals for ease of labeling, such as videos, to use as a reference while labeling
Signal Labeler (Signal Processing Toolbox)	Numeric arrays, MATLAB® timetables, and labeledSignalSet objects in the MATLAB workspace MAT-files and CSV files Audio files (WAVE, OGG, FLAC, AU, AIFF, AIFC, MP3, MPEG-4 AAC)	Time-based ROIs Time-based ROI features Time-based points Attributes Attribute features File-level labels Sublabels	Built-in peak labeling Built-in feature extraction Custom automation algorithms Speech detection Speech-to-text transcription (requires Audio Toolbox extended functionality for speech2text (Audio Toolbox))	Expand, collapse, and browse details of labeled data View signal spectra and spectrograms Label ROIs and points using the spectrogram Label signals in bulk Use Label Viewer to view and compare labels Audio playback Inspect audio file information Export extracted features to Classification Learner (Statistics and Machine Learning Toolbox)
Medical Image Labeler (Medical Imaging Toolbox)	2-D medical images and image series (DICOM or NIfTI files) 3-D medical image volume (DICOM, NIfTI, or NRRD files)	Pixel ROIs	Built-in automation algorithms Custom automation algorithms	View 3-D medical images in the coronal, sagittal, and transverse anatomical planes View 3-D medical images using customizable volume rendering Label multiple related images or image volumes in one app session

Related Topics

• Get Started with the Image Labeler
• Get Started with the Video Labeler
• Get Started with Ground Truth Labelling (Automated Driving Toolbox)
• Get Started with the Lidar Labeler (Lidar Toolbox)
• Using Signal Labeler App (Signal Processing Toolbox)
• Label Spoken Words in Audio Signals (Signal Processing Toolbox)
• Get Started with Medical Image Labeler (Medical Imaging Toolbox)