Opencv 如何使用支持向量机进行人员识别？

我运行OpenCV 2.4.2C++。< /P> 我正在尝试使用opencv进行人员识别

我使用的是VidTIMIT数据集，其中包含不同方向的不同人员

我正在使用CvSVM对这些人进行分类

我的问题是svm的输出总是相同的

我遵循的算法是：

基于Haar的人脸检测

调整面大小（58*58）

支持向量机训练

分类

现在，我想知道我在训练中是否做错了什么

我正在尝试这种方法，考虑5个（num_name）人，10个（num_图像）不同的图像

void runFaceDetectionRecognition(vector<Mat_<uchar> > &images){
vector<vector<Rect> > faces;
for (unsigned i=0; i<images.size(); ++i) {

    /// detection face
    vector<Rect> f;
    faceDetection(images[i], f);

    if (!f.empty()) {
        faces.push_back(f);

        /// I keep only the face
        Mat_<uchar> roi = ( images[i](f[0]) );

        /// resize
        resize(roi, roi, Size(58, 58));

        roi.copyTo(images[i]);            
    }
}

/// Set up parameters
CvSVMParams params;
params.svm_type    = CvSVM::C_SVC;
params.kernel_type = CvSVM::LINEAR;
params.term_crit   = cvTermCriteria(CV_TERMCRIT_ITER, 100, 1e-6);


/// Set up training data
float labels[num_name][num_images];
float label = 0;

/// different label for different person
for (unsigned i=0; i<num_name; ++i) {
    for (unsigned j=0; j<num_images; ++j)
        labels[i][j] = label;

    label++;
}

/// labeling matrix
Mat labelsMat(num_name*num_images, 1, CV_32FC1, labels);

/// unrolling images
float data[images.size()][58*58];
for (unsigned l=0; l<images.size(); ++l)

    for (unsigned i=0; i<58; ++i)
        for (unsigned j=0; j<58; ++j)
            data[l][j+58*i] = images[l].at<float>(i,j);


/// training matrix
Mat train((int) images.size(),58*58, CV_32FC1, data);
CvSVM svm(train, labelsMat, Mat(), Mat(), params);

/// Validation
valSVM(svm, train.rowRange(0, 1));
}

void runFaceDetectionRecognition（矢量和图像）{
向量面；
对于（无符号i=0；i您似乎正在使用完整的58*58面来训练您的支持向量机。为了使支持向量机工作，您需要使用OpenCV中已包含的PCA（主成分分析）等方法来降低维度（获取主成分）

如果将维数从58*58数组减少到n*n数组，其中n是主要特征，则SVM的训练将仅使用主要特征，并将产生改进的解决方案

有很多关于OpenCV人脸识别的文档，你可以开始。
这里的另一个答案是不正确的，说SVM必须使用PCA才能工作。我在没有PCA的128x128图像上使用了SVM，并取得了很好的效果。我用cohn kanade数据集做了类似的事情。下面是一些可能有帮助的源代码

vector<Mat> preImages;//Fill this with your images from your dataset
vector<int> labels;//Fill this with the labels from the dataset
vector<Mat> images;

CascadeClassifier haar_cascade;
haar_cascade.load("/usr/local/share/OpenCV/haarcascades/haarcascade_frontalface_alt.xml");
vector< Rect_<int> > faces;
Mat procFace;
cout << "images: " << preImages.size() << "    labels: " << labels.size() << endl;
for(unsigned int i = 0; i < preImages.size(); i++)
{
    procFace = preImages[i].clone();
    //haar_cascade.detectMultiScale(procFace, faces);
    haar_cascade.detectMultiScale(
            procFace,
            faces,
            1.1,
            3,
            CASCADE_FIND_BIGGEST_OBJECT|CASCADE_DO_ROUGH_SEARCH,
            Size(110, 110)
    );

    if(faces.size() > 0)
    {

        // Process face by face:
        Rect face_i = faces[0];
        // Crop the face from the image.
        Mat face = procFace(face_i);

        ////You can maybe use the equalizeHist function here instead//////
        face = illuminationComp(face);

        //crop face
        Rect cropped(face_i.width*0.18, face_i.height*0.2, int(face_i.width*0.7), int(face_i.height*0.78));
        Mat Cface = face(cropped);

        Mat face_resized;
        resize(Cface, face_resized, Size(128, 128), 1.0, 1.0, INTER_CUBIC);

        images.push_back(face_resized);
    }
}


//svm parameters:
SVMParams params = SVMParams();
params.svm_type = SVM::C_SVC;
params.kernel_type = SVM::LINEAR;
params.degree = 3.43; // for poly
params.gamma = 0.00225; // for poly / rbf / sigmoid
params.coef0 = 19.6; // for poly / sigmoid
params.C = 0.5; // for CV_SVM_C_SVC , CV_SVM_EPS_SVR and CV_SVM_NU_SVR
params.nu = 0.0; // for CV_SVM_NU_SVC , CV_SVM_ONE_CLASS , and CV_SVM_NU_SVR
params.p = 0.0; // for CV_SVM_EPS_SVR
params.class_weights = NULL; // for CV_SVM_C_SVC
params.term_crit.type = CV_TERMCRIT_ITER | CV_TERMCRIT_EPS;
params.term_crit.max_iter = 1000;
params.term_crit.epsilon = 1e-6;

if(images.size() == labels.size())
{
    cout << "Creating SVM Classification" << endl << endl;

    int rowsSize = images.size();
    int trainingArea = images[0].rows * images[0].cols;
    Mat trainingMat = Mat::zeros(rowsSize, trainingArea, CV_32FC1);
    int counter;


    for(int index = 0; index < rowsSize; index++)
    {
        counter = 0;
        for(int rows = 0; rows < images[0].rows; rows++)
        {
            for(int cols = 0; cols < images[0].cols; cols++)
            {
                trainingMat.at<float>(index, counter) = images[index].at<uchar>(rows,cols);
                    counter++;
            }
        }
    }


    Mat matLabels = Mat::zeros(labels.size(),1,CV_32FC1);
    for(size_t index = 0; index < labels.size(); index++)
    {
        matLabels.at<float>(index,0) = float(labels[index]);
    }

    if(trainingMat.rows == matLabels.rows)
    {
        SVM svm;
        svm.train(trainingMat,matLabels,Mat(),Mat(),params);
        svm.save("svm_model.yml");
    }
}

vector preImages；//用数据集中的图像填充
向量标签；//用数据集中的标签填充
矢量图像；
级联分类器haar_级联；
load（“/usr/local/share/OpenCV/haarcascades/haarcascade\u frontalface\u alt.xml”）；
向量<矩形>面；
垫面；
cout我也在建立一个项目，其中我对一个对象进行了分类。我使用了SVM和Bag of Features（BOf）/BOW的组合。在这种方法中，首先创建字典/代码本，然后训练SVM。结果相当好

你可以看看这个链接了解一下
你是否使用原始图像进行训练？它没有特征提取部分。如果我使用LBP提取特征并将其用作SVM训练的输入，怎么样？我是否需要将LBP特征转换为LBP直方图并进行训练？@user8430：提取lpb特征后，你需要计算相应的取消直方图，然后将该直方图向量传递给您的svm分类器。@user8430是的，我使用原始图像进行训练。在训练之前，我做的唯一一件事是对图像运行照明均衡并进行裁剪/对齐。
vector<Mat> preImages;//Fill this with your images from your dataset
vector<int> labels;//Fill this with the labels from the dataset
vector<Mat> images;

CascadeClassifier haar_cascade;
haar_cascade.load("/usr/local/share/OpenCV/haarcascades/haarcascade_frontalface_alt.xml");
vector< Rect_<int> > faces;
Mat procFace;
cout << "images: " << preImages.size() << "    labels: " << labels.size() << endl;
for(unsigned int i = 0; i < preImages.size(); i++)
{
    procFace = preImages[i].clone();
    //haar_cascade.detectMultiScale(procFace, faces);
    haar_cascade.detectMultiScale(
            procFace,
            faces,
            1.1,
            3,
            CASCADE_FIND_BIGGEST_OBJECT|CASCADE_DO_ROUGH_SEARCH,
            Size(110, 110)
    );

    if(faces.size() > 0)
    {

        // Process face by face:
        Rect face_i = faces[0];
        // Crop the face from the image.
        Mat face = procFace(face_i);

        ////You can maybe use the equalizeHist function here instead//////
        face = illuminationComp(face);

        //crop face
        Rect cropped(face_i.width*0.18, face_i.height*0.2, int(face_i.width*0.7), int(face_i.height*0.78));
        Mat Cface = face(cropped);

        Mat face_resized;
        resize(Cface, face_resized, Size(128, 128), 1.0, 1.0, INTER_CUBIC);

        images.push_back(face_resized);
    }
}


//svm parameters:
SVMParams params = SVMParams();
params.svm_type = SVM::C_SVC;
params.kernel_type = SVM::LINEAR;
params.degree = 3.43; // for poly
params.gamma = 0.00225; // for poly / rbf / sigmoid
params.coef0 = 19.6; // for poly / sigmoid
params.C = 0.5; // for CV_SVM_C_SVC , CV_SVM_EPS_SVR and CV_SVM_NU_SVR
params.nu = 0.0; // for CV_SVM_NU_SVC , CV_SVM_ONE_CLASS , and CV_SVM_NU_SVR
params.p = 0.0; // for CV_SVM_EPS_SVR
params.class_weights = NULL; // for CV_SVM_C_SVC
params.term_crit.type = CV_TERMCRIT_ITER | CV_TERMCRIT_EPS;
params.term_crit.max_iter = 1000;
params.term_crit.epsilon = 1e-6;

if(images.size() == labels.size())
{
    cout << "Creating SVM Classification" << endl << endl;

    int rowsSize = images.size();
    int trainingArea = images[0].rows * images[0].cols;
    Mat trainingMat = Mat::zeros(rowsSize, trainingArea, CV_32FC1);
    int counter;


    for(int index = 0; index < rowsSize; index++)
    {
        counter = 0;
        for(int rows = 0; rows < images[0].rows; rows++)
        {
            for(int cols = 0; cols < images[0].cols; cols++)
            {
                trainingMat.at<float>(index, counter) = images[index].at<uchar>(rows,cols);
                    counter++;
            }
        }
    }


    Mat matLabels = Mat::zeros(labels.size(),1,CV_32FC1);
    for(size_t index = 0; index < labels.size(); index++)
    {
        matLabels.at<float>(index,0) = float(labels[index]);
    }

    if(trainingMat.rows == matLabels.rows)
    {
        SVM svm;
        svm.train(trainingMat,matLabels,Mat(),Mat(),params);
        svm.save("svm_model.yml");
    }
}