[Insight-users] Image filtering and feature detection-

[Dan Mueller]

Hi Lars,

I used my ITK-based scripting program called "SharpImage"
    http://www.insight-journal.org/browse/publication/161

with the following commands
    Open "D:/Temp/wd3Yt.jpg#F2"
    MorphologicalOpen Kernel=itkFlatStructuringElement.Ball(itkSize(5,5))
    BinaryPixelMath Input1="wd3Yt.jpg"
Input2="wd3Yt_MorphologicalOpen.jpg" Operation="Sub"
    BinaryThreshold Lower=35 Upper=255

I'm not sure why your pipeline did not work. Can you please post your
source code?

HTH

Cheers, Dan

On 16 August 2010 16:37, Lars Friedrich Lars <lars-friedrich at gmx.net> wrote:
> Hello Dan,
>
> I also tried the WhiteTopHat-filter on the image. I used a BinaryBallStructuringElement-kernel with varying radius (1,3,5,6,10,20). However, I never got an output image that was that 'clean' as the one that you sent on the mailing list (wd3Yt_WhiteTopHat.jpg).
> Could you please tell me which kernel or possibly which exact pipeline did you use to produce this output? I face a comparable problem and would be interest in your pipeline.
> Thank you very much!!
>
> regards,
> lars
>
> p.s.: I attached the produced output with radius = 5.
>
> -------- Original-Nachricht --------
>> Datum: Mon, 16 Aug 2010 06:22:12 +0200
>> Von: Dan Mueller <dan.muel at gmail.com>
>> An: Ryan Smith <ryanleesmith at gmail.com>
>> CC: insight-users at itk.org
>> Betreff: Re: [Insight-users] Image filtering and feature detection-
>
>> Hi Ryan,
>>
>> You might consider using the "white top hat" operation to remove the
>> background:
>>     WhiteTopHat = I - Dilate( Erode(I) )
>> where I is the image, Erode is morphological erosion, and Dilate is
>> morphological dilation.
>>
>> You can find an implementation of this operation in:
>>     Code/BasicFilters/itkWhiteTopHatImageFilter.h
>>
>> Once the background is removed, a simple global intensity threshold
>> should suffice to segment the spots. The following filters may be
>> helpful for that task:
>>     Code/BasicFilters/itkBinaryThresholdImageFilter.h
>>     Code/Algorithms/itkOtsuThresholdImageFilter.h
>>     Code/Review/itkKappaSigmaThresholdImageFilter.h
>>
>> HTH
>>
>> Cheers, Dan
>>
>> On 15 August 2010 23:04, Ryan Smith <ryanleesmith at gmail.com> wrote:
>> > Hi-
>> > I am attempting to remove the background and detect features in the
>> > following image:
>> > http://i.imgur.com/wd3Yt.jpg
>> >
>> > I have a series of images in which the white circular spots travel and
>> the
>> > white vertical stripes remain stationary.  I would like to apply some
>> simple
>> > background subtraction to remove the white stripes then autodetect the
>> > intensity maxima associated with the circular features.
>> >
>> > A brief search provided the following results which address similar
>> problems
>> > using itkConnectedComponentFilter.  Is this what I want after my
>> background
>> > is subtracted?  Any example code on how to get the location and sizes
>> of the
>> > components? Thanks in advance-
>> >
>> > -Ryan