selectLabelsByGroup

Select ground truth data by label group name

Since R2020b

Syntax

gtLabel = selectLabelsByGroup(gTruth,labelGroups)

Description

gtLabel = selectLabelsByGroup(gTruth,labelGroups) selects ground truth data with the specified label group names labelGroups 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 Group Name

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

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

Inspect the label definitions. The object contains two label definitions in a 'vehicle' group. Ungrouped labels are in the group named 'None'.

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 in the group 'Vehicle' group.

groupNames = 'vehicle';
gtLidarLabel = selectLabelsByGroup(lidarLabelerGTruth,groupNames)

gtLidarLabel = 
  groundTruthLidar with properties:

          DataSource: [1x1 vision.labeler.loading.PointCloudSequenceSource]
    LabelDefinitions: [2x5 table]
           LabelData: [3x2 timetable]

View the labels returned by the function.

gtLidarLabel.LabelDefinitions

ans=2×5 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} 

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.

labelGroups — Label group names

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

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

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

unique(gTruth.LabelDefinitions.Group)

Example: 'Vehicles'

Example: "Vehicles"

Example: {'Vehicles','Signs'}

Example: ["Vehicles" "Signs"]

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 groups specified by the labelGroup input.

Version History

Introduced in R2020b