c++ - OpenCV 错误:断言失败 在未知函数中，

Question

我从其他解决方案中阅读了很多，但我仍然困惑我应该如何处理我的...

#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

#include <iostream>
#include <stdio.h>

using namespace std;
using namespace cv;

int main(int argc, const char** argv)
{
    //create the cascade classifier object used for the face detection
    CascadeClassifier face_cascade;
    //use the haarcascade_frontalface_alt.xml library
    face_cascade.load("haarcascade_frontalface_alt.xml");

    //setup video capture device and link it to the first capture device
    VideoCapture captureDevice;
    captureDevice.open(0);

    //setup image files used in the capture process
    Mat captureFrame;
    Mat grayscaleFrame;

    //create a window to present the results
    namedWindow("outputCapture", 1);

    //create a loop to capture and find faces
    while (true)
    {
        //capture a new image frame
        captureDevice >> captureFrame;

        //convert captured image to gray scale and equalize
        cvtColor(captureFrame, grayscaleFrame, CV_BGR2GRAY);
        equalizeHist(grayscaleFrame, grayscaleFrame);

        //create a vector array to store the face found
        std::vector<Rect> faces;

        //find faces and store them in the vector array
        face_cascade.detectMultiScale(grayscaleFrame, faces, 1.1, 3, CV_HAAR_FIND_BIGGEST_OBJECT | CV_HAAR_SCALE_IMAGE, Size(30, 30));

        //draw a rectangle for all found faces in the vector array on the original image
        for (int i = 0; i < faces.size(); i++)
        {
            Point pt1(faces[i].x + faces[i].width, faces[i].y + faces[i].height);
            Point pt2(faces[i].x, faces[i].y);

            rectangle(captureFrame, pt1, pt2, cvScalar(0, 255, 0, 0), 1, 8, 0);
        }

        //print the output
        imshow("outputCapture", captureFrame);

        //pause for 33ms
        waitKey(33);
    }
    return 0;
}

这是错误

OpenCV Error: Assertion failed in unknown function

错误似乎发生在“captureDevice >> captureFrame;”之后请指导我，这是从相机拍摄图像。

Answer 1

VideoCapture 似乎无法从您的相机抓取帧。添加此代码以检查帧抓取结果:

//create a loop to capture and find faces
while (true)
{
    //capture a new image frame
    captureDevice >> captureFrame;
    if (captureFrame.empty())
    {
        cout << "Failed to grab frame" << endl;
        break;
    }
    ...

如果是 VideoCapture 的问题，请检查您是否为相机安装了驱动程序。