openframeworks/openFrameworks — pull request #780 by danomatika (2011-10-19 00:12:37+00:00)
Title: opencv2 hole detection broken, here is the fix (thanks Golan)

opencv2 cvContourArea runs fabs on the area by default unless the (new!) third variable is set to true, this breaks hole detection since no negative areas are returned. Also, the current fabs calls are redundant.

Golan noticed that hole detection was off in 007 and I tracked this down, although the function update is not actually reflected in the opencv2 documentation ... blah. See this [disgruntled post](http://opencv-users.1802565.n2.nabble.com/cvContourArea-changed-API-tt4817692.html#none).

I tracked down the [diff for the open cv update](https://code.ros.org/trac/opencv/changeset/2927) that clearly shows the new variable, int oriented, controls whether negative areas are returned or not.

This is a resubmission of a previous [pull request](https://github.com/openframeworks/openFrameworks/pull/756) but now to the develop branch.