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Segmentation fault with opencv function

asked 2013-03-06 10:26:13 -0500

updated 2014-01-28 17:15:34 -0500

ngrennan gravatar image

I'm trying to detect a blob on a video feed with cvBlob lib. I think, I made a mistake with pointers, but I can't figure out where. Moreover, do I have to free some of this variable? The problem appears in row: unsigned int result=cvb::cvLabel(src_g, labelImg, blobs);

Mat& corridorProces(Mat& resultImg)
    Mat srcMat=resultImg.clone();
    cvtColor( resultImg, resultImg, CV_RGB2GRAY );
    IplImage src= resultImg.clone();
    IplImage *src_g= new IplImage(src);
    IplImage *src_g_inv=new IplImage(src);
    cvThreshold(src_g, src_g_inv,35,255, CV_THRESH_BINARY_INV);
    cvThreshold(src_g, src_g,40,255, CV_THRESH_BINARY);    
    IplImage *labelImg=cvCreateImage(cvGetSize(src_g), IPL_DEPTH_LABEL, 1);
    cvb::CvBlobs blobs;
    unsigned int result=cvb::cvLabel(src_g, labelImg, blobs);   
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This question is not related to ROS. It's better suited in cvBlob project mailing list or similar, not here.

Miquel Massot gravatar image Miquel Massot  ( 2013-03-06 10:47:28 -0500 )edit

Simply comment out all the code inside the function, and uncomment line by line until you find the one that give you a segmentation fault. It's not something related to ROS. It's a programming issue.

phbou72 gravatar image phbou72  ( 2013-03-06 17:09:16 -0500 )edit

The weird thing is that the algorithm implenented in Opencv works for 1 image, but when I try it in ROS, where the cv_brigde returns a cv::MAT() and I convert into Iplimage, I receive segmentation fault error.

zweistein gravatar image zweistein  ( 2013-03-06 18:43:05 -0500 )edit

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answered 2013-03-07 01:36:08 -0500

I changed to: IplImage *src_g=cvCloneImage(&src); and now its working. I dont understand why I got some times empty packages but now there is no more segmentation fault.

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Asked: 2013-03-06 10:26:13 -0500

Seen: 1,679 times

Last updated: Mar 07 '13