// model doesn't contain softmax layer
cv::dnn::ClassificationModel classification_model = cv::dnn::ClassificationModel( model, config );

// not apply softmax post process (default)
bool apply_softmax = classification_model.getSoftmaxPostProcessing(); // false

// apply softmax post process
apply_softmax = true;
classification_model.setEnableSoftmaxPostProcessing( apply_softmax );

// if enable softmax post process is true, confidences range is [0.0-1.0]
// if enable softmax post process is false, confidences range is varies by model
auto [classid, confidence] = model.classify( image );