Using OpenCV Contrib White Balancing on a Mat in C++

opencv-contrib-whitebalance.cpp

//install openCV contrib: https://cocoapods.org/pods/OpenCV2-contrib
/* 
//in Podfile: 

target 'MyProject' do
 pod 'OpenCV2-contrib', '~> 3.2'
*/

//pod install
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/xphoto/white_balance.hpp>


namespace myProject {
 void myFunction(){
  cv::Mat gray;
  cv::cvtColor(image, gray, CV_BGR2GRAY);
  cv::Ptr<cv::xphoto::WhiteBalancer> wb = cv::xphoto::createSimpleWB();
  wb->balanceWhite(gray, gray); 
 }
}