title: Automatic ROI/rectangle recognition
body: <p>I want to be able to pass on multiple images to python and detect the contour of the object in the picture. The pictures all represent money bills, hence the ROI is always going to be rectangular. Whatever ive tried, im not able to exactly detect the money bill. </p>
  
  <p>I tried canny edge detection but the transparent regions on the money bill (canadian money)<a href="https://fortunedotcom.files.wordpress.com/2016/01/gettyimages-185312445.jpg" rel="nofollow noreferrer">example of a canadian bill</a> make it hard to detect the whole bill.  Does anyone have any suggestions on how to automatically crop out just the money bill? Thanks in advance!</p>