addLabel

Add label definition to groundTruthMedical object

Since R2025a

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    Syntax

    addLabel(gTruthMed,labelName)
    addLabel(gTruthMed,labelName,Name=Value)

    Description

    addLabel(gTruthMed,labelName) adds the label definition labelName to the LabelDefinitions property of the specified groundTruthMedical object gTruthMed.

    example

    addLabel(gTruthMed,labelName,Name=Value) optionally specifies the pixel ID or color for the added label using one or more name-value arguments.

    Examples

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    Open Live Script

    Create Ground Truth Object

    Create ground truth data for two chest CT volumes and their corresponding label images, stored in the NIfTI file format. The files are a subset of the Medical Segmentation Decathlon data set [1]. Download the MedicalVolumNIfTIData.zip file from the MathWorks® website, then unzip the file. The size of the data file is approximately 76 MB.

    zipFile = matlab.internal.examples.downloadSupportFile("medical","MedicalVolumeNIfTIData.zip");
filepath = fileparts(zipFile);
unzip(zipFile,filepath)
dataFolder = fullfile(filepath,"MedicalVolumeNIfTIData");

    Create a VolumeSource object for the two CT volumes.

    filePath1 = fullfile(dataFolder,"lung_027.nii.gz");
filePath2 = fullfile(dataFolder,"lung_043.nii.gz");
source = {filePath1; filePath2};
dataSource = medical.labeler.loading.VolumeSource(source);

    Specify the names for two label definitions, left_lung and right_lung.

    labelDefNames = ["left_lung","right_lung"];

    Create a groundTruthMedical object by specifying the CT volume data source and label definition names.

    gTruthMed = groundTruthMedical(dataSource,labelDefNames);

    The label definitions table contains the specified two labels.

    gTruthMed.LabelDefinitions
    ans=2×3 table
        Name                LabelColor            PixelLabelID
    ____________    __________________________    ____________

    "left_lung"     0.8667    0.3294         0         1      
    "right_lung"    0.9294    0.6941    0.1255         2

    Add Labels to Ground Truth Object

    Add a third label definition, tumor, to the ground truth object.

    addLabel(gTruthMed,"tumor")

    Add a fourth label definition, edema, and specify the color and pixel label ID to associate with the new label.

    addLabel(gTruthMed,"edema",LabelColor=[0 1 0],PixelLabelID=10)

    The label definitions table now contains four label definitions.

    gTruthMed.LabelDefinitions
    ans=4×3 table
        Name                LabelColor            PixelLabelID
    ____________    __________________________    ____________

    "left_lung"     0.8667    0.3294         0          1     
    "right_lung"    0.9294    0.6941    0.1255          2     
    "tumor"         0.5216    0.0863    0.8196          3     
    "edema"              0         1         0         10

    [1] Medical Segmentation Decathlon. "Lung." Tasks. Accessed May 10, 2018. http://medicaldecathlon.com/.

    The Medical Segmentation Decathlon data set is provided under the CC-BY-SA 4.0 license. All warranties and representations are disclaimed. See the license for details.

    Input Arguments

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    Ground truth data, specified as a groundTruthMedical object. You can export a groundTruthMedical object from the Medical Image Labeler app or create one programmatically by using the groundTruthMedical function.

    Name of the label to add to the label definitions table, specified as a string scalar. The name must be different from those of the existing labels in the LabelDefinitions property of gTruth.

    Name-Value Arguments

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    Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

    Example: addLabel(gTruth,"lung",LabelColor=[1 0 0]) assigns the color red to the new label definition "lung".

    Pixel label ID for the added label, specified as a positive integer. The pixel label ID must be different from the IDs of existing labels in the LabelDefinitions property of gTruth.

    Example: PixelLabelID=7

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical

    Color for the added label, specified as an RGB triplet. An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0, 1], for example, [0.4 0.6 0.7]. By default, the function assigns the next color in the default colormap used by Medical Image Labeler.

    Version History

    Introduced in R2025a

    See Also

    Apps

    Objects

    Functions