Hi, I am trying to detect 4 corners of a regular paper sheet. i have tried all the ways canny/sobel/polygon detection/line detection they all work fine
if and only if the whole paper is visible
if one or more of the corner is obstructed by users hand (if he is trying to write something on paper) one of the corners get lost and i really need all four or an estimation of all four
so is there a way if i know three points of a polygon and i can calculate/guess where the fourth one will be if its obstructed found this article which seems to do the opposite of what i want -> http://stackoverflow.com/questions/17087446/how-to-calculate-perspective-transform-for-opencv-from-rotation-angles
or is there a way to remove the hand from the image by using some tech color detection etc?
any help will be appreciated