title: Algorithm to detect credit card sized card
body: <p>I want to detect a credit card sized card in image. The card can be any card eg identity card, member card. Currently, I am thinking to use Canny Edge, Hough Line and Hough Circle to detect the card. But the process will be tedious when I want to combine all the information of Hough Line and Hough Circle to locate the card. Some people suggest threshold and findContour but the color of card can be similar to the background which make this method difficult to achieve the desired result. Is there any kernel and method which can help me to detect the card?</p>
  
  <p><a href="https://i.stack.imgur.com/bHszC.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/bHszC.jpg" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/aDlJK.png" rel="noreferrer"><img src="https://i.stack.imgur.com/aDlJK.png" alt="enter image description here"></a></p>