Updating OpenCV CvNormalBayesClassifier

我试图使用CvNormalBayesClassifier来训练我的程序来学习皮肤像素颜色。我有一组训练图像和反应图像。反应图像是黑白的，皮肤区域被标记为白色。下面是我的代码

CvNormalBayesClassifier classifier;
for (int i = 0; i < numFiles; i++) {
    string trainFile = "images/" + int2str(i) + ".jpg";
    string responseFile = "images/" + int2str(i) + "_mask.jpg";
    Mat trainData = imread(trainFile, 1);
    Mat responseData = imread(responseFile, CV_LOAD_IMAGE_GRAYSCALE);
    trainData = trainData.reshape(1, trainData.rows * trainData.cols);
    responseData = responseData.reshape(0, responseData.rows * responseData.cols);
    trainData.convertTo(trainData, CV_32FC1);
    responseData.convertTo(responseData, CV_32FC1);
    classifier.train(trainData, responseData, Mat(), Mat(), i != 0);
}

但是，它给出了以下错误，

The function/feature is not implemented (In the current implementation the new training data must have absolutely the same set of class labels as used in the original training data) in CvNormalBayesClassifier::train