[Insight-users] Issues with the HoughTransform2DCirclesImageFilter class

[Karthik Krishnan]

On Thu, 2006-06-29 at 16:10 -0700, Shlomo Kashani. wrote:
> Hi,
> I have an image of an iris which was successfully segmented using the
> canny edge (see image 056R_3_canny.png ) detector as the input to the
> HoughTransform2DCirclesImageFilter class. I experimented a lot with
> the HoughTransform2DCirclesImageFilter but no matter what I do with
> different combinations of its parameters I am unable to detect a
> circle in the edge mapped image (see image ). It seems that if ask the
> class to locate 1 circle than it will draw a circle that has nothing
> to do with the actual location of the circle in the input image. What
> is more, if I ask for N circles then N circles will be drawn
> regardless of the actual number of circles in the image. Has anyone
> had any success with this class? Is there a test case I can run or an
> image that this class was tested on? 

The nightly test for this can be found at
Testing/Code/BasicFilters/itkHoughTransform2DCirclesImageTest.cxx

You can run it as "ctest -R HoughTransform2DCirclesImageTest -V" from
the ITK build directory (if you built ITK with BUILD_TESTING ON).

>  
> Here are the parameters I used you can run execute the class with
> these parameter and the attached image to replicate the problem.
>  
> HoughTransform2DCirclesImageFilter.exe 056R_3_canny.png
> 056R_3_1_Hough.png 4 200 400 0 1 10
> Computing Hough Map
> Found 4 circle(s).
> Center: [496, 264]
> Radius: 232.949
> Center: [166, 72]
> Radius: 325.086
> Center: [96, 540]
> Radius: 327.406
> Center: [686, 73]
> Radius: 290.867
>  
> HoughTransform2DCirclesImageFilter.exe 056R_3_canny.png
> 056R_3_1_Hough.png 1 200 500 0 1 10
> Computing Hough Map
> Found 1 circle(s).
> Center: [96, 538]
> Radius: 347.539
>  
> HoughTransform2DCirclesImageFilter.exe 056R_3_canny.png
> 056R_3_1_Hough.png 1 300 400 0 1 10
> Computing Hough Map
> Found 1 circle(s).
> Center: [78, 72]
> Radius: 366
>  
> HoughTransform2DCirclesImageFilter.exe 056R_3_canny.png
> 056R_3_1_Hough.png 1 200 400 0 1 10
> Computing Hough Map
> Found 1 circle(s).
> Center: [496, 264]
> Radius: 232.949
>  
> Thank you very much for your help,
>  
> Shlomo. 
>  
> 
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