Cannot display image loaded from disk in release build

edit

The first thing to do (And this is true for absolutely any program, in any language, in any configuration) is to check your input before processing it. So, modify your code with this lines:

cv::Mat img = cv::imread(in_path);

if(img.empty())
{
    cout << "Error! Could not read the image from disk"
    return -1;
}

cv::imshow("image", img); // No exception should be thrown here now

And going back to your problem, most probably you have a different Release directory, and from that one, your image is not visible. so, if you have your image in MyProject/Debug/img.png, it will work in debug mode, but when your exe is in MyProject/Release/myprogram.exe, trying to load a relative path will fail

I think that the problem may lie outside the OpenCV. OpenCV itself can't read jpg files (it is pretty complicate format), and thus it is using other libraries on your computer that can read jpg (I don't remember which ones). Maybe the problem is within those libraries. Or OpenCV failed to find appropriate dlls or something.

You can put this theory to the test. Change format of your jpg files to pgm or ppm - very simple formats that simply store image buffer on disk without any compression (pgm is 1 channel image, and ppm is 3 channel image). I think OpenCV reading them without using any third party libraries. Check if your release build can read images in this format.

Are you using all the functionality in those lib files in your code? For example, are you using object detection and calibration in the same executable? I feel that a number of users indicate that they are using all the libraries provided while they should only be using the ones they really need in the code.

I just added these and ONLY these to the Project > Properties > Configuration Properties > Linker > Input > Additional Dependencies:

opencv_core243d.lib
opencv_imgproc243d.lib
opencv_highgui243d.lib
opencv_ml243d.lib
opencv_video243d.lib
opencv_features2d243d.lib
opencv_calib3d243d.lib
opencv_objdetect243d.lib
opencv_contrib243d.lib
opencv_legacy243d.lib
opencv_flann243d.lib