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    <div class="moz-cite-prefix">Hi Matt,<br>
      <br>
      yes, I currently use the ITK iterators, but I have the following
      problem. <br>
      <br>
      Standard code looks like:<br>
      <br>
      itk::ImageRegionIterator<ImageType1> it( radius, myImage,
      region );<br>
      itk::ImageRegionIterator<ImageType2> featureIt1( radius,
      featureImage1, region );<br>
      itk::ImageRegionIterator<ImageType3> featureIt2( radius,
      featureImage2, region );<br>
      <br>
      it.GotoBegin();<br>
      featureIt1.GotoBegin();<br>
      featureIt2.GotoBegin();<br>
      <br>
      while(!it.IsAtEnd())<br>
      {<br>
         // do some complicated processing stuff with or without
      feature1 and/or feature2<br>
      <br>
        ++it;<br>
        ++featureIt1;<br>
        ++featureIt2;<br>
      }<br>
      <br>
      I only know at runtime, whether featureImage1 and/or featureImage2
      are available. If<br>
      featureImage1 or featureImage2 is NULL, a segmentation fault
      occurs.<br>
      <br>
      Therefore, I have currently implemented:<br>
      <br>
      itk::ConstNeighborhoodIterator<ImageType1> it( radius,
      myImage, region );<br>
      <br>
      it.GotoBegin();<br>
      <br>
      while(!it.IsAtEnd())<br>
      {<br>
         currentIndex=it.GetIndex();<br>
         if( featureImage1.IsNotNull())<br>
         {<br>
              // use featureImage1->GetPixel(currentIndex) to process
      feature 1<br>
          }<br>
          if( featureImage2.IsNotNull())<br>
         {<br>
              // use featureImage2->GetPixel(currentIndex) to process
      feature 2<br>
         }<br>
         <br>
         // do some other stuff<br>
      <br>
        ++it;<br>
      }<br>
      <br>
      The Image::GetPixel() method is quite time-consuming and therefore
      I look for a more efficient method<br>
      to implement this code (without writing four different versions).<br>
      <br>
      Any suggestions?<br>
      <br>
      Best regards,<br>
      Jan<br>
      <br>
      On 03/11/2014 06:12 AM, Matt McCormick wrote:<br>
    </div>
    <blockquote
cite="mid:CALzTN-RujRXRUR6UQh=3QT-bcqD8YAi8eir4bn23LBzqYLyoQA@mail.gmail.com"
      type="cite">
      <div dir="ltr">Hi Jan,
        <div><br>
        </div>
        <div>To iterator through an Image or VectorImage, use the
          Iterators as described in the Software Guide [1]</div>
        <div><br>
        </div>
        <div>HTH,</div>
        <div>Matt</div>
        <div><br>
        </div>
        <div>[1] <a moz-do-not-send="true"
            href="http://itk.org/ItkSoftwareGuide.pdf">http://itk.org/ItkSoftwareGuide.pdf</a></div>
      </div>
      <div class="gmail_extra"><br>
        <br>
        <div class="gmail_quote">On Thu, Mar 6, 2014 at 8:23 AM, Jan
          Ehrhardt <span dir="ltr"><<a moz-do-not-send="true"
              href="mailto:ehrhardt@imi.uni-luebeck.de" target="_blank">ehrhardt@imi.uni-luebeck.de</a>></span>
          wrote:<br>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi folks,<br>
            <br>
            I want to iterate through a vector image without an
            iterator. My approach was:<br>
            <br>
                MultiChannelImageType::AccessorType accessor =
            pImage->GetPixelAccessor();<br>
                MultiChannelImageType::InternalPixelType* pBuffer =
            pImage->GetBufferPointer();<br>
            <br>
                for( OffsetValueType i = from; i < to; ++i )<br>
                {<br>
                    vecPixel = accessor.Get(*pBuffer, i);<br>
                }<br>
            <br>
            but the results are not correct (see bug(?) below). If the
            bug(?) in DefaultVectorPixelAccessor is corrected (
            m_OffsetMultiplier = l ) the behaviour of standard itk
            iterators change. I assume, I don't understand the
            parameters of DefaultVectorPixelAccessor::Get() correctly.<br>
            How can I use the DefaultVectorPixelAccessor correctly?<br>
            <br>
            best,<br>
            jan
            <div class="HOEnZb">
              <div class="h5"><br>
                <br>
                On 03/06/2014 12:25 PM, Jan Ehrhardt wrote:<br>
                <blockquote class="gmail_quote" style="margin:0 0 0
                  .8ex;border-left:1px #ccc solid;padding-left:1ex">
                  Hi folks,<br>
                  <br>
                  there is a bug in DefaultVectorPixelAccessor (ITK
                  4.4.0):<br>
                  <br>
                    void SetVectorLength(VectorLengthType l)<br>
                    {<br>
                      m_VectorLength = l;<br>
                      m_OffsetMultiplier = ( l - 1 );<br>
                    }<br>
                  <br>
                    DefaultVectorPixelAccessor(VectorLengthType l)<br>
                    {<br>
                      m_VectorLength = l;<br>
                      m_OffsetMultiplier = l - 1;<br>
                    }<br>
                  <br>
                  OffsetMultiplier should be m_OffsetMultiplier = l;<br>
                  <br>
                  Best regards,<br>
                  Jan<br>
                  <br>
                </blockquote>
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