Howtosignalprocessing
How to detect rectangle in OpenCV Python?
Find the approximate contour for each of the contours. If the number of vertex points in the approximate contour is 4 then we compute the aspect ratio to make a difference between the rectangle and square. If the aspect ratio is between 0.9 and 1.1 we say it is a square else a rectangle See the below pseudocode.
What is cv2 arcLength?
cv2. arcLength() is used to calculate the perimeter of the contour. If the second argument is True then it considers the contour to be closed. Then this perimeter is used to calculate the epsilon value for cv2. approxPolyDP() function with a precision factor for approximating a shape.
