title: OpenCV cv::Mat displays empty gray images? Cant find the reason
body: <p>I just want to display this "img1.jpg" image in a c++ project with using opencv libs for future processes, but it only displays an empty gray window. What is the reason of this. Is there a mistake in this code? please help!</p>
  
  <p>Here is the code;</p>
  
  <pre><code> Mat img1;
   char imagePath[256] = "img1.jpg";
   img1 = imread(imagePath, CV_LOAD_IMAGE_GRAYSCALE);
   namedWindow("result", 1);
   imshow("result", img1);
  </code></pre>
  
  <p>Thanks...</p>