Ask questions on using Emgu CV with VB
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Joined: Wed Jul 06, 2016 4:04 am


Post by kroach » Wed Jul 06, 2016 4:27 am

I am trying to find the lines in an image using the Houghlines method. I have a problem with the LinesFound parameter which should be an array of vectors containing the rho and theta values of the lines found. I need the rho and theta values for additional processing. Can anyone help with the declaration of the LinesFound parameter?

Code: Select all

        Dim Camera0 As Capture = New Capture(0)
        Dim imgOriginal As Mat = Camera0.QueryFrame
        Dim imgGrayscale As New Mat(imgOriginal.Size, DepthType.Cv8U, 1)
        Dim imgBlurred As New Mat(imgOriginal.Size, DepthType.Cv8U, 1)
        Dim imgCanny As New Mat(imgOriginal.Size, DepthType.Cv8U, 1)
        Dim RhoRes As Double = 2
        Dim Threshold As Integer = 50
        Dim ThetaRes As Double = Math.PI / 90
        Dim LinesFound As ??????

        CvInvoke.CvtColor(imgOriginal, imgGrayscale, ColorConversion.Bgr2Gray) ' greyscale
        CvInvoke.GaussianBlur(imgGrayscale, imgBlurred, New Size(5, 5), 1.5) ' filter noise
        CvInvoke.Canny(imgBlurred, imgCanny, 50, 200, 3) ' edge extraction

        CvInvoke.HoughLines(imgCanny, LinesFound, RhoRes, ThetaRes, Threshold, 10, 5)
        ibOriginal.Image = imgOriginal              'update image boxes
        ibCanny.Image = imgCanny

Posts: 4
Joined: Sun Oct 23, 2016 7:09 pm

Re: CvInvoke.HoughLines

Post by beaulieu » Sun Oct 23, 2016 7:12 pm

I'm having the same problem. Did you ever solve this issue. If yes please let me know. I'm pulling my hair out here.

If you know of a good source of information for emguCv commands for please let me know as well.


Posts: 1
Joined: Sun Jan 29, 2017 4:03 pm
Location: Poland

Re: CvInvoke.HoughLines

Post by alicjanowakxd » Mon Feb 20, 2017 4:53 pm

Good info and straight to the point. Thank you
try it now

Posts: 13
Joined: Sun Jun 10, 2018 1:52 am

CvInvoke HoughLines

Post by Michaelgrawl » Sun Sep 02, 2018 4:06 am

I built and referred to Emgu.CV.World.dll in my project. When I was trying to call the method like

IntPtr complexImage = CvInvoke.cvCreateImageimage.Width image.Height, Emgu.CV.CvEnum.IPL_DEPTH.IPL_DEPTH_32F, 2;

Visual studio complains that it could not find the definitions for both Emgu.CV.CvEnum.IPL_DEPTH.IPL_DEPTH_32F and cvSetZero. Am I still missing anything in my project?

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