Method FindLaser2

ScanThread.cpp:212–292

Find the laser based on an image without the laser in it and with the laser in it Return an array that is the height of the image with a floating-point sub-pixel value of the laser You need to release the vector that gets returned

// Return an array that is the height of the image with a floating-point sub-pixel value of the laser
// You need to release the vector that gets returned
vector<float>* ScanThread::FindLaser2(IplImage *withLaser)
{
    // subtract the image with the laser in (withLaser) it from the image without the laser (noLaser)
    // to find where the laser is

    IplImage *withLaserBlur = cvCloneImage(withLaser);
    cvSmooth(noLaser, noLaserBlur, CV_GAUSSIAN, BLUR_AMOUNT);

    // copy images so we don't modify given images
    IplImage *noLaserCopy = cvCloneImage(noLaserBlur);
    IplImage *withLaserCopy = cvCloneImage(withLaserBlur);

    // create a single-channel image for processing
    CvSize sz = cvSize(noLaser->width & -2, noLaser->height & -2);
    IplImage *bwNoLaser = cvCreateImage(sz, 8, 1);
    IplImage *bwWithLaser = cvCreateImage(sz, 8, 1);
    IplImage *subImage = cvCreateImage(sz, 8, 1);

    // create the return vector
    vector<float> *pxLocations = new vector<float>(sz.height, -1);

    // convert color images to black and white

    // the cvCvtColor function segfaults on windows.  Not sure why.
    cvCvtColor(noLaserCopy, bwNoLaser,CV_BGR2GRAY);
    cvCvtColor(withLaserCopy, bwWithLaser,CV_BGR2GRAY);

    // subtract the no laser image from the with-laser image
    // if nothing else moved, we should just see where the laser is now
    cvSub(bwWithLaser, bwNoLaser, subImage);

    //captureThread->SendFrame(subImage);

    // set up single-pixel access to the subtracted and original image
    RgbImage noLaserPx(noLaserCopy);
    BwImage subPx(subImage);
    BwImage bwWithLaserPx(bwWithLaser);

    // identify the laser in the top 25 rows
    for (int h=0;h<25;h++)
    {
        (*pxLocations)[h] = FindBrightestPointInRow(subPx, h, sz.width);
    }

    // compute the brightness of those laser hits
    float brightSum = 0, brightAverage = 0;

    for (int h=0;h<25;h++)
    {
        brightSum += bwWithLaserPx[h][  int( (*pxLocations)[h] + 0.5)  ];
    }
    brightAverage = brightSum / 25.0;

    int bestPx;

    // for loop that loops through every row in the image
    for (int h = 25; h < sz.height; h++)
    {