selectLabels

Select ground truth data by label name or type

Since R2020b

Syntax

gtLabel = selectLabels(gTruth,labels)

Description

gtLabel = selectLabels(gTruth,labels) selects ground truth data of the specified label names or types labels from a groundTruthLidar object gTruth. The function returns a corresponding groundTruthLidar object gtLabel that contains only the selected labels. If gTruth is a vector of groundTruthLidar objects, then the function returns a vector of corresponding groundTruthLidar objects that contain only the selected labels.

Examples

Select Ground Truth Lidar Labels by Label Name or Label Type

Load a groundTruthLidar object containing labels of various groups, types, and names into the workspace.

lidarDir = fullfile(matlabroot,'toolbox','lidar','lidardata','lidarLabeler');
addpath(lidarDir)
load('lidarLabelerGTruth.mat')

Inspect the label definitions. The object contains label definitions of types Cuboid and Scene with various label names.

lidarLabelerGTruth.LabelDefinitions

ans=4×5 table
         Name          Type            LabelColor              Group       Description
    ______________    ______    ________________________    ___________    ___________

    {'car'       }    Cuboid    {[0.5862 0.8276 0.3103]}    {'vehicle'}    {0x0 char} 
    {'bike'      }    Cuboid    {[     0.5172 0.5172 1]}    {'vehicle'}    {0x0 char} 
    {'pole'      }    Cuboid    {[0.6207 0.3103 0.2759]}    {'None'   }    {0x0 char} 
    {'vegetation'}    Cuboid    {[          0 1 0.7586]}    {'None'   }    {0x0 char} 

Create a new groundTruthLidar object that contains only the label definitions with the name "car".

labelNames = "car";
gtLidarLabel = selectLabels(lidarLabelerGTruth,labelNames);

View the label definitions of the returned groundTruthLidar object.

gtLidarLabel.LabelDefinitions

ans=1×5 table
     Name       Type            LabelColor              Group       Description
    _______    ______    ________________________    ___________    ___________

    {'car'}    Cuboid    {[0.5862 0.8276 0.3103]}    {'vehicle'}    {0x0 char} 

Create a new groundTruthLidar object that contains the label definitions from lidarLabelerGTruth for only the labels of type Cuboid.

labelType = labelType.Cuboid;
gtLidarLabel = selectLabels(lidarLabelerGTruth,labelType)

gtLidarLabel = 
  groundTruthLidar with properties:

          DataSource: [1x1 vision.labeler.loading.PointCloudSequenceSource]
    LabelDefinitions: [4x5 table]
           LabelData: [3x4 timetable]

View the label definitions of the returned groundTruthLidar object.

gtLidarLabel.LabelDefinitions

ans=4×5 table
         Name          Type            LabelColor              Group       Description
    ______________    ______    ________________________    ___________    ___________

    {'car'       }    Cuboid    {[0.5862 0.8276 0.3103]}    {'vehicle'}    {0x0 char} 
    {'bike'      }    Cuboid    {[     0.5172 0.5172 1]}    {'vehicle'}    {0x0 char} 
    {'pole'      }    Cuboid    {[0.6207 0.3103 0.2759]}    {'None'   }    {0x0 char} 
    {'vegetation'}    Cuboid    {[          0 1 0.7586]}    {'None'   }    {0x0 char} 

Input Arguments

gTruth — Ground truth lidar data

groundTruthLidar object | vector of groundTruthLidar objects

Ground truth lidar data, specified as a groundTruthLidar object or vector of groundTruthLidar objects.

labels — Label names or types

one or more label names | one or more label types

Label names or types, specified as one or more label names or one or more label types. Specify one or more label names as a character vector, string scalar, cell array of character vectors, or vector of strings. Specify one or more label types as a labelType enumeration or vector of labelType enumerations.

To view all distinct label names in a groundTruthLidar object, enter the first of these commands at the MATLAB^® command prompt. To view all distinct label types in a groundTruthLidar object, enter the second.

unique(gTruth.LabelDefinitions.Name)
unique(gTruth.LabelDefinitions.Type)

Example: 'car'

Example: "car"

Example: {'car','lane'}

Example: ["car" "lane"]

Example: labelType.Cuboid

Example: [labelType.Cuboid labelType.Scene]

Output Arguments

gtLabel — Ground truth with only selected labels

groundTruthLidar object | vector of groundTruthLidar objects

Ground truth with only the selected labels, returned as a groundTruthLidar object or vector of groundTruthLidar objects.

Each groundTruthLidar object in the gtLabel output corresponds to a groundTruthLidar object in the gTruth input. The returned objects contain only those labels from the input ground truth objects that are of the label types or the label names specified in the labels input.

Version History

Introduced in R2020b