<p dir="ltr">Hi pengpeng, </p>
<p dir="ltr">The first cast to unsigned char is overflowing - 179 = 435 -  256.</p>
<p dir="ltr">Hth,<br>
Matt </p>
<div class="gmail_quote">On Aug 4, 2013 10:17 PM, &quot;pengpeng&quot; &lt;<a href="mailto:helloliupengxin@gmail.com">helloliupengxin@gmail.com</a>&gt; wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Dear ITK Friend<br>
<br>
I want to get any position pixel value of 3D DICOM volume.<br>
But when I use iterator.get and getpixel, the results are different.<br>
The first one reads 179 while the second reads 435. Can anyone help?<br>
Thanks a lot.<br>
<br>
&lt; iterator code &gt;<br>
              InternalImageType::Pointer imageForI =reader-&gt;GetOutput();<br>
              InternalImageType::SizeType regionSize;<br>
              regionSize[0]=1;<br>
              regionSize[1]=1;<br>
              regionSize[2]=1;<br>
<br>
              InternalImageType::IndexType regionIndex;<br>
              regionIndex[0]=128;<br>
              regionIndex[1]=128;<br>
              regionIndex[2]=2;<br>
<br>
              InternalImageType::RegionType region;<br>
              region.SetSize(regionSize);<br>
              region.SetIndex(regionIndex);<br>
<br>
              itk::ImageRegionConstIterator&lt;InternalImageType&gt;<br>
imageIterator(imageForI,region);<br>
              while(!imageIterator.IsAtEnd())<br>
                {<br>
                unsigned char val = imageIterator.Get();<br>
                std::cout &lt;&lt;&quot; Pixel is &quot;&lt;&lt; (int)val &lt;&lt; std::endl;<br>
                ++imageIterator;<br>
                }<br>
&lt; end iterator code &gt;<br>
&lt;getpixel code&gt;<br>
             InternalImageType::IndexType pi={128,128,2};<br>
             std::cout&lt;&lt;&quot;pixel is<br>
&quot;&lt;&lt;reader-&gt;GetOutput()-&gt;GetPixel(pi)&lt;&lt;std::endl;<br>
&amp;lt;end getpixel code&gt;<br>
<br>
<br>
<br>
<br>
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