在 Fisherfaces.train() 方法中获取 OpenCV 错误"Image step is wrong"

Question

我正在使用OpenCV v2.4.1

这是我正在使用的代码

#include "opencv2/opencv.hpp"
#include <iostream>
#include <fstream>
#include <sstream>
using namespace cv;
using namespace std;
Mat toGrayscale(InputArray _src) {
    Mat src = _src.getMat();
    // only allow one channel
    if(src.channels() != 1)
        CV_Error(CV_StsBadArg, "Only Matrices with one channel are supported");
    // create and return normalized image
    Mat dst;
    cv::normalize(_src, dst, 0, 255, NORM_MINMAX, CV_8UC1);
    return dst;
}
void read_csv(const string& filename, vector<Mat>& images, vector<int>& labels, char separator = ';') {
    std::ifstream file(filename.c_str(), ifstream::in);
    if (!file)
        throw std::exception();
    string line, path, classlabel;
    while (getline(file, line)) {
        stringstream liness(line);
        getline(liness, path, separator);
        getline(liness, classlabel);
        images.push_back(imread(path, 0));
        labels.push_back(atoi(classlabel.c_str()));
    }
}
int main(int argc, const char *argv[]) {
    // check for command line arguments
    /*if (argc != 2) {
        cout << "usage: " << argv[0] << " <csv.ext>" << endl;
        exit(1);
    }*/
    // path to your CSV
    string fn_csv = string("at.txt");
    // images and corresponding labels
    vector<Mat> images;
    vector<int> labels;
    // read in the data
    try {
        read_csv(fn_csv, images, labels);
    } catch (exception&) {
        cerr << "Error opening file "" << fn_csv << ""." << endl;
        exit(1);
    }
    // get width and height
    //int width = images[0].cols;
    int height = images[0].rows;
    // get test instances
    Mat testSample = images[images.size() - 1];
    int testLabel = labels[labels.size() - 1];
    // ... and delete last element
    images.pop_back();
    labels.pop_back();
    // build the Fisherfaces model
    Ptr<FaceRecognizer> model = createFisherFaceRecognizer();
    model->train(images, labels);
    // test model
    int predicted = model->predict(testSample);
    cout << "predicted class = " << predicted << endl;
    cout << "actual class = " << testLabel << endl;
    // get the eigenvectors
    Mat W = model->eigenvectors();
    // show first 10 fisherfaces
    for (int i = 0; i < min(10, W.cols); i++) {
        // get eigenvector #i
        Mat ev = W.col(i).clone();
        // reshape to original size AND normalize between [0...255]
        Mat grayscale = toGrayscale(ev.reshape(1, height));
        // show image (with Jet colormap)
        Mat cgrayscale;
        applyColorMap(grayscale, cgrayscale, COLORMAP_JET);
        imshow(format("%d", i), cgrayscale);
    }
    waitKey(0);
    return 0;
}

at.txt输入文件的内容：

./

at/s10/2.pgm;9./at/s10/7.pgm;9./at/s10/6.pgm;9./at/s10/9.pgm;9./at/s10/5.pgm;9

现在的问题是，只要我用这个pgm文件，就可以了。但是当我指定任何jpg文件而不是pgm时，我收到以下错误

OpenCV错误：图像步长错误（矩阵不连续，因此其数量 行数无法更改）在未知函数中，文件 ......\src\opencv\modulES\core\SRC\matrix.cpp，第 801 行

到目前为止，我能够追踪错误来自 Fisherfaces.train（） --> cv：：Mat.reShape（）

但是我毫无头绪，可能是什么原因。请帮忙。

Answer 1

这个解决方案对我有用！

早些时候，我在项目属性中添加了发布和调试库。现在我已经删除了所有已发布的库，并且它运行完美。

Answer 2

当您构建渔人脸模型时。

Ptr<FaceRecognizer> model = createFisherFaceRecognizer();

您需要传递两个参数

createFisherFaceRecognizer(int num_components=0, double threshold=DBL_MAX);

此页面包含有关createFisherFaceRecognizer如何工作的更多信息