Stat() 函数 returns 值为 -1，因此无法访问文件属性。我该如何纠正这个问题？

Question

此代码是使用OpenCV进行人脸识别的训练代码。它裁剪和均衡图像以仅包含脸部。唯一发生的错误是 stat() 函数 returns 值为 -1 并且未访问 D:\Project\Original 下的文件。

The output of the following is:

-1 Cannot access Folder1

请帮助我理解为什么会这样。当使用 OpenCV 2.4.9

在 CodeBlocks 16.01 上编译相同代码（稍作更改）时，不会发生此错误

#include <iostream>
#include <fcntl.h>
#include <sys/stat.h>
#include <string>
#include <string.h>
#include <fstream>
#include <string.h>
#include <direct.h>
#include <dirent.h>
#include <opencv/cv.h>
#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/xfeatures2d.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/objdetect.hpp>

using namespace std;
using namespace cv;

char* IMG_SEP = "_";
int MAX_IMAGE_NAME_SIZE = 100;
int IM_HEIGHT = 200;
int IM_WIDTH = 200;
String face_cascade_name = "haarcascade_frontalface_alt.xml";
String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
CascadeClassifier face_cascade;
CascadeClassifier eyes_cascade;
vector<string> fileNames;
vector<string> outputLabel;
vector<string> outputPath;
char* srcDirName = "D:/Project/Original";
char* dstDirName = "D:/Project/Cropped";
char* CSV_PATH = "D:/Project/Cropped/myCSV.csv";

void getFileNames(char* path) {
    DIR *dir;
    struct stat info;
    struct dirent *ent;
    if ((dir = opendir(path)) != NULL) {
        while ((ent = readdir(dir)) != NULL) {
            if ((!strcmp(ent->d_name, ".") == 0) && (!strcmp(ent->d_name, "..") == 0)) {

                char* temp = (char*)malloc(256);
                sprintf_s(temp, 100, "%s%s", path, ent->d_name);

                // THIS IS WHERE THE DEBUGGER GOES. STAT RETURNS -1
                if (stat(temp, &info) != 0) {
                    cout << stat(temp, &info) << " ";
                    cout << "Cannot access " << ent->d_name << "\n";
                }


                if (info.st_mode & S_IFREG) {
                    string temp1 = ent->d_name;
                    temp1 = temp1.substr(0, temp1.rfind(IMG_SEP));
                    temp1 = dstDirName + temp1;
                    _mkdir(temp1.c_str());
                    fileNames.push_back(temp);
                }

                else if (info.st_mode & S_IFDIR) {
                    char* temp1 = (char*)malloc(256);
                    sprintf_s(temp1, 100,  "%s/%s", dstDirName, ent->d_name);
                    _mkdir(temp1);
                    strcat_s(temp, sizeof temp, "/");
                    getFileNames(temp);
                }
            }
        }
        closedir(dir);
    }
    else {
        cout << "Could not open the required image directory";
    }
}

void printVector(vector<string> images) {
    for (int i = 0; i < images.size(); i++) {
    cout << images[i] << "\n";
    }
}

void initializeDetector() {
    if (!face_cascade.load(face_cascade_name)) {
        cout << "Error while loading the face detection cascade classifier";
    }

    if (!eyes_cascade.load(eyes_cascade_name)) {
        cout << "Error while loading the eye detection cascade classifier";
    }
}

void detectAndStore(Mat image, String imageName) {
    vector<Rect> faces;
    vector<Rect> eyes;
    Mat frame_grey;
    cvtColor(image, frame_grey, CV_BGR2GRAY);
    equalizeHist(frame_grey, frame_grey);
    face_cascade.detectMultiScale(frame_grey, faces, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(30, 30));
    //if(faces.size() == 1){
    for (size_t i = 0; i < faces.size(); i++) {
        Mat faceROI = frame_grey(faces[i]);
        eyes_cascade.detectMultiScale(faceROI, eyes, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(30, 30));
        if (eyes.size() < 1) {
            continue;
        }
        resize(faceROI, faceROI, Size(IM_WIDTH, IM_HEIGHT), 1.0, 1.0, INTER_CUBIC);
        String fileName = imageName;
        int posBeg = fileName.rfind('/') + 1;
        String label = fileName.substr(posBeg, MAX_IMAGE_NAME_SIZE);
        int posEnd = label.rfind('.');
        String labelNameWithNum = label.substr(0, posEnd);
        cout << "Cropping and storing " << labelNameWithNum << "\n";
        int pos = labelNameWithNum.rfind(IMG_SEP);
        String labelNameWithoutNum = labelNameWithNum.substr(0, pos);
        String destination = dstDirName + labelNameWithoutNum + "/" + label;
        outputPath.push_back(destination);
        outputLabel.push_back(labelNameWithoutNum);
        equalizeHist(faceROI, faceROI);
        imwrite(destination, faceROI);
        break;
    }
}

void processImages() {
    initializeDetector();
    for (int i = 0; i < fileNames.size(); i++) {
        Mat image = imread(fileNames[i], CV_LOAD_IMAGE_COLOR);
        detectAndStore(image, fileNames[i]);
    }
}

void createCSV() {
    ofstream myFile;
    myFile.open(CSV_PATH, ios_base::out);
    for (int i = 0; i < outputPath.size(); i++) {
        myFile << outputPath[i] << ";" << outputLabel[i] << "\n";
    }
    myFile.close();

}

int main() {
    getFileNames(srcDirName);
    processImages();
    createCSV();
    return 0;
}

Answer 1

sprintf_s(temp, 100, "%s%s", path, ent->d_name); -> sprintf_s(temp, 100, "%s/%s", path, ent->d_name);

（加斜杠）

这是通过检查 "temp" 在失败统计点处进行的简单调试。

由于 dirent 没有随 MSVC 一起提供，也许它是您粘贴的 dirent.h 中的错误..但您稍后使用 ent->d_name 执行了 %s/%s，并且 "path" 来自您的硬编码常量，所以我认为您在从 "code blocks"

移植时犯了一个错误

Answer 2

由于您使用的是 OpenCV 3.1，因此可以使用 glob。这避免了像您这样的复杂代码及其错误。

您的 getFileNames 基本上减少为：

vector<cv::String> fileNames; // This must be a cv::String now

...

void getFileNames(std::string path)
{
    cv::glob(path,fileNames,false);
}

您可以看到 glob 用于许多其他答案，例如here.

Stat() 函数 returns 值为 -1，因此无法访问文件属性。我该如何纠正这个问题？

Stat() function returns value -1 and thus, file attributes cannot be accessed. How do I correct this?

c++

visual-studio

opencv

visual-studio-2015

opencv3.1