Opencv – Issue with reading an image using “cv::imread” function in OpenCv

opencvvisual-studio-2008

I have got a problem with some basic OpenCV code.
Here is my code:

 cv::Mat src;
 src=imread("Calibration.bmp",0);

 if (src.empty())
  cout << "Cannot load image" << " ";
 else
  cout << src.cols << " " << src.rows << " ";

Unfortunatelly cv::imread returns NULL matrix with any kind of input image (I have tried .bmp, .jpg). The filename seems to be working fine (program does not end with error), as using wrong filename generates an error message.
I have tried using oldstyle "CvLoadImage" but same result occurred.
Does anyone have any idea how to fix this?

Best Answer

Ok, I fixed the problem... Problem arises when you are mixing up release and debug OpenCV libs. I've changed paths and libs names in project properties and "cv::imread" works just fine.

Related Solutions

OpenCV – cvLoadImage() can NOT load JPG image

This is because the path you are giving to your program is not actually pointing towards anything.

If you are putting the image in the same folder then you need to call

cvLoadImage("hello.jpg");

if the image is anywhere else then as @vasile commented you need to call

cvLoadImage("C:\\hello.jpg");

Also I have edited your code so it exits if the image is not loaded properly

#include "stdafx.h"
#include <cv.h>
#include <highgui.h>

int _tmain(int argc, _TCHAR* argv[])
{
  IplImage* img = cvLoadImage("C:/hello.jpg");

  if (!img)
  {
    printf("Image can NOT Load!!!\n");
    return 1;
  }

  cvNamedWindow("myfirstwindow");
  cvShowImage("myfirstwindow", img);

  cvWaitKey(0);
  cvReleaseImage(&img);

return 0;
}

C++ – OpenCV 2.4.2 imread function causing runtime error

I have tried the code you have given. It works perfectly fine with my installation of OpenCV.

However I am getting a warning at the line:

char* imgPath = "logo.png";

main.cpp:6:21: warning: deprecated conversion from string constant to 'char*' [-

Wwrite-strings]

Which i think is nothing serious to make the code crash, however it might be the problem in your case, as I am not using VC++ to compile.

What you can try to check if this is the issue is to replace imgPath with directly the string, so the code will now be like

Mat img = imread("logo.png");

Best Answer

Related Solutions

OpenCV – cvLoadImage() can NOT load JPG image

C++ – OpenCV 2.4.2 imread function causing runtime error

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