Support the 'Oriented' area flag in contourArea

[cvalente56]

The contourArea has an optional parameter 'oriented' which when true "the function returns a signed area value, depending on the contour orientation (clockwise or counter-clockwise)"

Is it possible we can add support for this?

I'm experiencing duplication in contours, and this will help to resolve it. Duplicate contours in opencv

Documentation http://docs.opencv.org/