我遇到了这个问题，
当我在vs2010(debug)(opencv 2.4.0)中运行facerec_demo.cpp时，程序出现以下错误：
OpenCV错误：图像步长不正确（矩阵不连续，因此其行数无法更改），未知函数，文件......\src\opencv\modules\core>\src\matrix.cpp，第801行。
这个错误导致我查看了facerec.cpp中的以下代码行：
(Fisherfaces::train(InputArray src, InputArray _lbls)
Mat data = asRowMatrix(src, CV_64FC1); <-- this gets a exeption, not handled.
我使用过PGM图像数据库，以下是我的原始*facerec_demo.cpp*文件
#include "stdafx.h"
#include <opencv2/opencv.hpp>
#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <sstream>
using namespace cv;
using namespace std;
vector<string> split_at_commas(const string& row)
{
vector<string> res;
istringstream buf(row);
string s;
while (getline(buf, s, ';'))
res.push_back(s);
return res;
}
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);
std::ifstream file(_T("D:\\Users\\PC ACER\\Documents\\mycsv4.csv"));
if (!file)
throw std::exception();
string line="", path="", classlabel="";
while (getline(file, line)) {
//vector<string> values = split_at_commas(line);
stringstream liness(line);
getline(liness, path, ';');
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(argv[1]);
// 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;
}