CODEWITHSUNDEEP
c++opencvdetectiongeometry
kerry_13
kerry_13

Reputation: 289

What is V4L/AVLD in opencv?

I follow the instruction in this page: http://wiki.elphel.com/index.php?title=OpenCV_Tennis_balls_recognizing_tutorial to detect the tennis ball. This code may be run for Python and it's requirement is V4L/AVLD for Morphological operations. it's use function cvClose() and cvOpen() to dilate and erode the mask. I write my code in c++, so cvDilate() and cvErode() are used instead, but the result isn't as good as the that site.

Here is my result:output.jpg. (i'm sorry, because i don't have reputation enough to post image T_T) Here is my full code:

#include "highgui.h"
#include "cv.h"
void main()
{
    IplImage* img = cvLoadImage("tennis.jpg",1);
    CvSize size = cvGetSize(img);
    IplImage *hsv = cvCreateImage(size, IPL_DEPTH_8U, 3);
    cvCvtColor(img, hsv, CV_BGR2HSV);
    CvMat *mask = cvCreateMat(size.height, size.width, CV_8UC1);
    cvInRangeS(hsv, cvScalar(0.11*256, 0.60*256, 0.20*256, 0),
                    cvScalar(0.14*256, 1.00*256, 1.00*256, 0), mask);
    cvReleaseImage(&hsv);
    IplConvKernel *se21 = cvCreateStructuringElementEx(21, 21, 10, 10, CV_SHAPE_RECT, NULL);
    IplConvKernel *se11 = cvCreateStructuringElementEx(11, 11, 5,  5,  CV_SHAPE_RECT, NULL);
    cvErode(mask, mask, se21); 
    cvDilate(mask, mask, se11);   
    cvReleaseStructuringElement(&se21);
    cvReleaseStructuringElement(&se11);

    /* Copy mask into a grayscale image */
    IplImage *hough_in = cvCreateImage(size, 8, 1);
    cvCopy(mask, hough_in, NULL);
    cvSmooth(hough_in, hough_in, CV_GAUSSIAN, 15, 15, 0, 0);

    /* Run the Hough function */
    CvMemStorage *storage = cvCreateMemStorage(0);
    CvSeq *circles = cvHoughCircles(hough_in, storage,CV_HOUGH_GRADIENT, 4, size.height/10, 100, 40, 0, 0);
    cvReleaseMemStorage(&storage);
    int i;
    for (i = 0; i < circles->total; i++) {
         float *p = (float*)cvGetSeqElem(circles, i);
         CvPoint center = cvPoint(cvRound(p[0]),cvRound(p[1]));
         CvScalar val = cvGet2D(mask, center.y, center.x);
         if (val.val[0] < 1) continue;
             cvCircle(img,  center, 3,             CV_RGB(0,255,0), -1, CV_AA, 0);
             cvCircle(img,  center, cvRound(p[2]), CV_RGB(255,0,0),  3, CV_AA, 0);
             cvCircle(mask, center, 3,             CV_RGB(0,255,0), -1, CV_AA, 0);
             cvCircle(mask, center, cvRound(p[2]), CV_RGB(255,0,0),  3, CV_AA, 0);
    }

    cvNamedWindow( "Output", CV_WINDOW_AUTOSIZE );
    cvShowImage( "Output", img );
    cvNamedWindow( "mask", CV_WINDOW_AUTOSIZE );
    cvShowImage( "mask", mask );
    cvWaitKey(0);
}

Can someone help me to get V4L/AVLD and improve this code ? thank you very much.

Upvotes: 1

Views: 472

Answers (1)

Froyo
Froyo

Reputation: 18477

V4L/AVLD is for webcam. It doesn't have anything to do with the code or algorithm. http://allonlinux.free.fr/Projets/AVLD/

If you are using Linux, v4l-utls package needs to be installed in order to use webcam.

Upvotes: 2

Related Questions