C++，OpenCV，在尝试显示图像时收到此错误“OpenCV（4.3.0）错误：断言失败（size.width>0 && size.height>0）”

Question

I am trying to set up opencv for c++ in visual studio. I have download OpenCV and set it up and can successfully include opencv without any errors. When trying the following code I get and error: "OpenCV(4.3.0) Error: Assertion failed (size.width>0 && size.height>0)" after line 11.

#include <opencv2\opencv.hpp>
#include <iostream>

using namespace std;
using namespace cv;

int main()
{
    Mat img = imread("C:/Users/Whity/Desktop/OpenCVRoot/OpenCV/Win10BG_Red.png", IMREAD_COLOR);

    imshow("Display Window", img);

    waitKey(10);

    return 0;
}

I have looked at numerous other threads where many much of the discussion was about an incorrect path to the image, or using the wrong file type. (png, jpg, jpeg) I have quadruple checked my path and have tried other paths and other images, all resulting in the same error. Any ideas?

Answer 1

Since you're on Windows, you must use \\ to denote the directory separator:

Mat img = imread("C:\\Users\\Whity\\Desktop\\OpenCVRoot\\OpenCV\\Win10BG_Red.png", IMREAD_COLOR);

Even after the corrections to the path above, I suspect that you may still be having trouble due to a permissions error. Your Desktop cannot be accessed by certain programs unless you give it Administrator access. You either need to open up Visual Studio as an Administrator, or move the image somewhere else on your computer so that it has access. I will update my answer. So for the former, exit Visual Studio, then right click on the icon and click on Run As Administrator . Once you open it up, try loading up the image again. If you're still having trouble, move the image somewhere else like in your Documents directory on your computer and try reading it from there.