我正在使用OpenCV SVM实现来双向预测图像特征的重要性。因此,我正在对正面和负面图像特征进行培训,并在{0,1}中寻找分类。OpenCV SVM总是预测更高级别的标签
我遇到的问题是,在训练之后,SVM总是预测具有更高/更高类别标签的类。我可以更改训练数据集的标签,并且此问题仍然存在。我仔细检查了生成的标签和培训cv :: Mat矩阵,并没有发现任何问题。
下面是我的SVM类和相应的SVM参数
//Populate the SVM parameters
void SVM::setSVMParams()
{
params.svm_type = cv::SVM::C_SVC;
params.kernel_type = cv::SVM::RBF;
params.term_crit = cv::TermCriteria(CV_TERMCRIT_ITER, 100, 1e-6);
params_set = true;
}
//Train the SVM with the given data
void SVM::train(cv::Mat train_data, cv::Mat labels)
{
//Set the SVM parameters if they haven't been already
if (!params_set)
{
setSVMParams();
}
svm.train(train_data, labels, cv::Mat(), cv::Mat(), params);
}
//Based on training, predict the class of the given data
float SVM::predict(cv::Mat sample)
{
return svm.predict(sample, false);
}
这里是函数负责生成训练数据和相应的标签
//Creates the appropriate training data and class labels for subsequent SVM training according to supplied D threshold
void Matchings::createSVMTrainingObjects(const float t_D, const float positive_label, const float negative_label, bool print_info)
{
cv::Mat train_data_l((int)matchings_list.size(), 132, CV_32FC1);
cv::Mat labels_l((int)matchings_list.size(), 1, CV_32FC1);
int num_pos = 0;
int num_neg = 0;
for (int i = 0; i < matchings_list.size(); i++)
{
matching_d entry = matchings_list[i];
//Important feature, label 1
if (entry.D > t_D)
{
labels_l.at<float>(i) = positive_label;
num_pos++;
}
//Unimportant feature, label -1
else
{
labels_l.at<float>(i) = negative_label;
num_neg++;
}
int j = 0;
//Copy feature into current row of openCV matrix
train_data_l.at<float>(i, j++) = entry.feature.x;
train_data_l.at<float>(i, j++) = entry.feature.y;
train_data_l.at<float>(i, j++) = entry.feature.scale;
train_data_l.at<float>(i, j++) = entry.feature.angle;
for (int k = 0; k < 128; k++)
{
train_data_l.at<float>(i, j + k) = entry.feature.vec[k];
}
}
std::cout << "For training: #+ves=" << num_pos << ", #-ves=" << num_neg << std::endl;
train_data = train_data_l;
labels = labels_l;
}
最后,这里是函数实际调用SVM预测结果以保留重要的图像特征
matchingslist ASIFT::filterFeaturesWithSVM(matchingslist matchings, SVM& svm)
{
matchingslist new_matchings;
for (int i = 0; i < (int)matchings.size(); i++)
{
cv::Mat first = Utility::keypointToMat(matchings[i].first);
cv::Mat second = Utility::keypointToMat(matchings[i].second);
//If both features are of importance, retain them
if (svm.predict(first) == 1.0f && svm.predict(second) == 1.0f)
{
new_matchings.push_back(matchings[i]);
}
else
{
std::cout << "Feature removed" << std::endl;
}
}
return new_matchings;
}
您应该为您的问题提供最少的工作示例。您正在使用的代码,示例数据。没有它,没有人可以帮助 - 只有猜测。 – lejlot
谢谢,是的,我应该做的..我已经更新了代码示例的问题,以了解我如何与SVM交互 –