title: Cropping a cross rectangle from image using c#
body: <p>What I want to do is basically cropping a rectangle from an image. However, it should satisfy some special cases:  </p>
  
  <ol>
  <li>I want to crop an angled rectangle on image.</li>
  <li>I don't want to rotate the image and crop a rectangle :)</li>
  <li>If cropping exceeds the image size, I don't want to crop an empty background color. </li>
  </ol>
  
  <p>I want to crop from back of the starting point, that will end at starting point when rectangle size completed. I know I couldn't explain well so if I show what I want visually:</p>
  
  <p><img src="https://i.stack.imgur.com/TYngs.jpg" alt="enter image description here"> </p>
  
  <p>The blue dot is the starting point there, and the arrow shows cropping direction. When cropping exceeds image borders, it will go back to the back of the starting point as much as, when the rectangle width and height finished the end of the rectangle will be at starting point.</p>
  
  <p>Besides this is the previous question I asked:</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/8699103/how-to-crop-a-cross-rectangle-from-an-image-using-c">How to crop a cross rectangle from an image using c#?</a></li>
  </ul>
  
  <p>In this question, I couldn't predict that a problem can occur about image dimensions so I didn't ask for it. But now there is case 3. Except case three, this is exactly same question. How can I do this, any suggestions?</p>