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I tried this out myself and got everything to compile and function, but the program would never use more than one processor. Is there something special you also need to do other than have opencv 2.4.3 compiled with the Using TBB selected?

Here's a sample code (my actual looping body was much more substantial, this was just a test to make sure that yes, no matter what it wasn't using more than one core)

class Parallel_Test : public cv::ParallelLoopBody
{
private:
double* const mypointer;



public:
Parallel_Test(double* pointer)
: mypointer(pointer){

}
     void operator() (const Range& range) const
{
         //This constructor needs to be here otherwise it is considered an abstract class.
//             qDebug()<<"This should never be called";
}

    void operator ()(const cv::BlockedRange& range) const
    {

        for (int x = range.begin(); x < range.end(); ++x){

            mypointer[x]=x;

        }


    }



};


 //TODO Loop pixels in parallel
     double t = (double)getTickCount();

    //TEST PARALELL LOOPING AT ALL
    double data1[1000000];



        cv::parallel_for(BlockedRange(0, 1000000),  Parallel_Test(data1));

        t = ((double)getTickCount() - t)/getTickFrequency();
        qDebug() << "Parallel TEST time " << t << endl;


        t = (double)getTickCount();

        for(int i =0; i<1000000; i++){

            data1[i]=i;
        }
        t = ((double)getTickCount() - t)/getTickFrequency();
        qDebug() << "SERIAL Scan time " << t << endl;