blorgggg's profile - activity

Just adding to this. The way to get that nice settings window to pop up is by running (It is the SET command) capture.se

So after trying powers of two resolutions, and getting the same results when passing it through the graycode decode func

So after trying powers of two resolutions, and getting the same results when passing it through the graycode decode func

So after trying powers of two resolutions, and getting the same results when passing it through the graycode decode func

Graycode Pattern: Irregular and off-center?? I have been struggling trying to get the Structured light examples going wi

Graycode Pattern: Irregular and off-center?? I have been struggling trying to get the Structured light examples going wi

Graycode Pattern: Irregular and off-center?? I have been struggling trying to get the Structured light examples going wi

Graycode Pattern: Irregular and off-center?? I have been struggling trying to get the Structured light examples going wi

Yeah tried that, it was never going through :/

Graycode Pattern: Irregular and off-center?? I have been struggling trying to get the Structured light examples going wi

Graycode Pattern: Irregular and off-center?? I have been struggling trying to get the Structured light examples going wi

Stereo Calibration for CharUco Boards? Are there any examples for calibrating two cameras simultaneously with CharUco Bo

Dang!!!!!!!!! Thanks for helping validate that i was not losing my mind! Unfortunately i did not compile it myself, i am

Structured Light Module Missing "decode" function In the java version (and hence the ported OpenCV for Unity version I a

ATTENTION: If you are new to this (like me), make note that the new implementation is "parallel_for_" (with a trailing underscore!) not "parallel_for" !!! Otherwise it will just run your loop in serial! AHH!

@Daniil Osokin and especially @Vladislav Vinogradov for pointing this out!

I just saw in the new opencv 2.4.3 that they added a universal parallel_for. So following this example: http://answers.opencv.org/question/3730/how-to-use-parallel_for/

I tried to implement it myself. I got it all functioning with my code, but when I timed its processing vs a similar loop done in a typical serial fashion with a regular "for" command, the results were insignificantly faster, or often a tiny bit slower!

I thought maybe this had something to do with my pushing into vectors or something (im a pretty big noob to parallel processing), so i set up a test loop of just running through a big number and it still doesn't work

check it out:

code:

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;

Here's the output: output:

Parallel TEST time 0.00415479

SERIAL Scan time 0.00204597

that example was just a test case, my actual loop that i hope to parallelize takes about 1.5 seconds normally (i'm doing ICP registration over millions of 3D points) and the parallel_for does not improve that at all. What's even more telling is that only one processor is ever used at a time. Even if calling the threads was inefficient, it should at least be doing this with multiple cores. This leads me to believe that something is wrong.

Is there anything extra one needs to do to make sure it uses more than one processor? I implmented all this, and it runs fine, just not any faster than a serial loop.

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;