Ok, I guess that you just want to extract an RGB 2D slice from a 3D RGB image. <br><br>Then, your mistake is OutputPixelType. RGBPixels are vectors of unsigned chars, and can't be directly converted to scalars (just unsigned chars). The fastest fix could be this:<br>
<br> typedef itk::Image<RGBPixelType,2> OutputPixelType_extract_RGB;<br><br>By the way, you probably missed writer->SetFileName() in your code ;)<br><br>HTH<br><br><br><br><div class="gmail_quote">2011/7/1 john smith <span dir="ltr"><<a href="mailto:mkitkinsightuser@gmail.com">mkitkinsightuser@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Well, to explain what I am trying to do. I have created a 3D RGB image as a result of a segmentation procedure. To create this image I had used itkLabelOverlayImageFilter.So this image was created by a greyscale image and a label image, so I get the result of the initial greyscale image and the label image with blue color. When I have tried to extract a slice from the image I got this error<br>
<i>error C2440: 'static_cast' : cannot convert from 'itk::RGBPixel<TComponent>' to 'unsigned char' </i>. I have included my code in the begining of this topic. I also cannot understand the second step very well.Why I should do something like this? What should I do for this task?<br>
<br>Thanks for your response<div><div></div><div class="h5"><br><br><br><div class="gmail_quote">2011/7/1 Juan Vidal <span dir="ltr"><<a href="mailto:juanvidalallende@gmail.com" target="_blank">juanvidalallende@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex">
Well, I don't know exactly what your are trying to do, but in my opinion you could probably split your problem:<br><br>1) Extract the desired 2D RGB slice from the 3D RGB image (ExtractImageFilter should work).<br>2) Convert the 2D RGB slice to unsigned char<br>
<br>The second point depends on the purpose of your application. You might want to extract one of the channels, or perhaps convert the RGB image to grayscale in some fashion...<br><br>HTH<div><div></div><div><br>
<br><br><br><div class="gmail_quote">
2011/6/30 john smith <span dir="ltr"><<a href="mailto:mkitkinsightuser@gmail.com" target="_blank">mkitkinsightuser@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex">
Could somebody explain in some words what must be done in order to extract a 2D slice from a RGB 3D image? I am trying to find an example (but I didn't find anything) and I am reading the docs but I am totally lost. This task may be very easy but I really need some help.<br>
Any response would be very useful.<br><br>Thanks in advace<div><div></div><div><br><br><div class="gmail_quote">2011/6/30 john smith <span dir="ltr"><<a href="mailto:mkitkinsightuser@gmail.com" target="_blank">mkitkinsightuser@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex">You may have right as it should work properly.It is the first time I am working with RGB images. But what changes should be done?<br>
<br>Thanks for yoyr response<div><div></div><div><br><br><div class="gmail_quote">2011/6/30 robert tamburo <span dir="ltr"><<a href="mailto:robert.tamburo@gmail.com" target="_blank">robert.tamburo@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex"><div>Do you really expect the filter to extract a 2D image of unsigned char pixels from a 3D image of RGB pixels?</div>
<div><br></div><div><div class="gmail_quote"><div><div></div><div>On Thu, Jun 30, 2011 at 3:07 PM, john smith <span dir="ltr"><<a href="mailto:mkitkinsightuser@gmail.com" target="_blank">mkitkinsightuser@gmail.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex"><div><div></div><div>Hello to all,<br><br>I am trying to read an RGB image, then use the
ExtractImageFilter and finally, write the RGB slice. I have written the
following code, but I get this error <br><i>error C2440: 'static_cast' : cannot convert from 'itk::RGBPixel<TComponent>' to 'unsigned char' </i>. Do you know what I am doing wrong?<br>
<br>Thanks in advance<br><br>///////// code //////////////<br>typedef itk::RGBPixel<unsigned char> RGBPixelType;<br> typedef itk::Image<RGBPixelType,3> RGBImageType;<br><br> typedef itk::ImageFileReader< RGBImageType > ReaderType_RGB;<br>
<br> ReaderType_RGB::Pointer reader_RGB = ReaderType_RGB::New();<br><br> reader_RGB->SetFileName( "output.hdr" );<br> reader_RGB->Update();<br><br><br> typedef unsigned char OutputPixelType_extract_RGB;<br>
typedef itk::Image< OutputPixelType_extract_RGB, 2 > OutputImageType_extract_RGB;<br><span style="background-color:rgb(255, 255, 255)"> typedef itk::ExtractImageFilter< RGBImageType, OutputImageType_extract_RGB > FilterType_extract_RGB;</span><br>
<span style="background-color:rgb(255, 255, 51)">FilterType_extract_RGB::Pointer filter_extract_RGB = FilterType_extract_RGB::New();</span><br><div><br> RGBImageType::RegionType inputRegion =<br> reader_RGB->GetOutput()->GetLargestPossibleRegion();<br>
<br><br> RGBImageType::SizeType size = inputRegion.GetSize();<br>
<br> // get the size of the hole 3D image<br> size_x = size[0];<br> size_y = size[1];<br> size_z = size[2];<br> <br> // get slices of z coordiante<br> size[2] = 0; <br><br> RGBImageType::IndexType start = inputRegion.GetIndex();<br>
ui->verticalScrollBar_z->setRange(0,size_z-1);<br> unsigned int sliceNumber = ui->verticalScrollBar_z->value();<br> start[2] = 10; <br> <br><br> RGBImageType::RegionType desiredRegion;<br> desiredRegion.SetSize( size );<br>
desiredRegion.SetIndex( start );<br><br> filter_extract_RGB->SetExtractionRegion( desiredRegion );<br><br> typedef itk::ImageFileWriter< OutputImageType_extract_RGB > WriterType_RGB;<br> WriterType_RGB::Pointer writer_RGB = WriterType_RGB::New();<br>
writer_RGB->SetFileName( "z.png" );<br><br> filter_extract_RGB->SetInput( reader_RGB->GetOutput() );<br> writer_RGB->SetInput( filter_extract_RGB->GetOutput() );<br><br> try <br> { <br>
writer_RGB->Update(); <br> } <br> catch( itk::ExceptionObject & err ) <br> { <br> std::cerr << "ExceptionObject caught !" << std::endl; <br> std::cerr << err << std::endl; <br>
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<br></blockquote></div><br><br clear="all"><br></div></div><font color="#888888">-- <br>Juan Vidal Allende<br>
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