Import the 'Class' column from a csv file using the 'Object ID' map. Expects the 'Object ID's in csv match with the ones from the QuPath image.

importClassfromCsv.groovy

import qupath.lib.scripting.QP
import qupath.lib.objects.classes.PathClass
import java.io.BufferedReader
import java.io.FileReader

import qupath.lib.io.*

def csvFilePath  = Dialogs.promptForFile(null)


// Read the CSV file
def csvData = []
try {
    def reader = new BufferedReader(new FileReader(csvFilePath))
    def line
    while ((line = reader.readLine()) != null) {
        csvData.add(line.split(','))
    }
    reader.close()
} catch (Exception e) {
    e.printStackTrace()
}

// Find the column indices for 'Object ID' and 'Class'
def objectIdIndex = -1
def classIndex = -1

def headerRow = csvData[0]
headerRow.eachWithIndex { value, index ->
    if (value == 'Object ID') {
        objectIdIndex = index
    } else if (value == 'Class') {
        classIndex = index
    }
}

// Create the 'Object ID' to 'Class' map
def objectIdToClassMap = [:]

csvData.eachWithIndex { row, rowIndex ->
    if (rowIndex > 0) {
        def objectId = row[objectIdIndex]
        def objectClass = row[classIndex]
        objectIdToClassMap[objectId] = objectClass
    }
}

// Print the 'Object ID' to 'Class' map

def pathClasses = getQuPath().getAvailablePathClasses()
print(pathClasses)
for (def detection : QP.getDetectionObjects()) {
def measurementList = detection.getMeasurementList()

objID = detection.getID().toString()
def newClassID = objectIdToClassMap[objID]
def newClass = PathClass.fromString(newClassID)
if (!pathClasses.contains(newClass)){
    pathClasses.add(newClass)}
detection.setPathClass(newClass)
}

// Fire update event


println("Done")