Calculate minimum area rectangle for a polygon

Question

I have a need to calculate the minimum area rectangle (smallest possible rectangle) around the polygon.

The only input i have is the number of points in polygon.

soryy for the incomplete information . Yes i have the co-ordinates of the points also

Thanks

Answer 1

Use the rotating calipers algorithm for a convex polygon, or the convex hull otherwise. You will of course need the coordinates of the points in the polygon, not just the number of points.

Answer 2

Obviously, you'll need the coordinates of the points to get the answer. If the rectangle is aligned to the X and Y aces, then the solution is trivial. If you want the smallest possible rectangle, at any angle, then you'll need to do some sort of optimization process.

Answer 3

This is called Minimum Bounding Box, it's most basic algorithm used in OCR packages. You can find an implementation using Rotating Calipers from the OpenCV package. Once you get the source code, check out this file,

cv/src/cvrotcalipers.cpp

The method you need is cvMinAreaRect2().