selectLabelsByName

Select ground truth data by label name

Since R2020b

Syntax

gtLabel = selectLabelsByName(gTruth,labelNames)

Description

gtLabel = selectLabelsByName(gTruth,labelNames) selects ground truth data of the specified label names labelNames 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

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

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

Inspect the label definitions. The object contains label definitions with various 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 = selectLabelsByName(lidarLabelerGTruth,labelNames)

gtLidarLabel = 
  groundTruthLidar with properties:

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

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} 

Input Arguments

gTruth — Ground truth lidar data

groundTruthLidar object | vector of groundTruthLidar objects

Lidar ground truth data, specified as a groundTruthLidar object or vector of groundTruthLidar objects.

labelNames — Label names

character vector | string scalar | cell array of character vectors | vector of strings

Label names, specified as a character vector, string scalar, cell array of character vectors, or vector of strings.

To view all distinct label names in a groundTruthLidar object gTruth, enter this command at the MATLAB^® command prompt.

unique(gTruth.LabelDefinitions.Name)

Example: 'car'

Example: "car"

Example: {'car','lane'}

Example: ["car" "lane"]

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 gtLabel corresponds to a groundTruthLidar object in the gTruth input. The returned objects contain only the labels that are of the label names specified by the labelNames input.

Version History

Introduced in R2020b