OpenCV錯誤：斷言失敗 <scn == 3 ::scn == 4> 功能不明

Question

我從其他解決方案中讀了很多書，但我仍然困惑於我該怎么辦...

#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;
}

這是錯誤

OpenCV錯誤：斷言在未知函數中失敗

似乎錯誤發生在“ captureDevice >> captureFrame;”之后 請指導我，這是從相機拍攝圖像。

Answer 1

VideoCapture似乎無法從您的相機中抓取幀。 添加以下代碼以檢查抓幀結果：

//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的問題，請檢查是否已安裝相機的驅動程序。

Answer 2

好吧，我想我知道發生了什么。 我嘗試運行該程序，它運行良好。

您可能尚未鏈接所需的DLL。。確保（如果使用Windows） opencv / bin包含在環境變量中。 這是我的CMakeLists.txt文件，它使您的工作更輕松，

cmake_minimum_required(VERSION 2.6 FATAL_ERROR)
project(SO_example)

FIND_PACKAGE(OpenCV REQUIRED)

SET (SOURCES
    #VTKtoPCL.h
    main.cpp
    )

add_executable(so_example ${SOURCES})
target_link_libraries(so_example ${OpenCV_LIBS})