[Insight-users] RE : Mean image

[Bill Lorensen]

Josiane,

You cannot divide an image by a number with the "/" operator. We have
not defined the "/" operator or other numeric operators on itk::Image.
You must use a filter to do this.

Bill

On Mon, May 26, 2008 at 11:33 AM, Yankam Njiwa  Josiane Adrienne
<njiwa at biomed.ee.ethz.ch> wrote:
> Hi Cameron,
>
> Thanks a lot for your answer, but i think my problem occured when i try to perfom division. Here is my complete code. I don't exactly how i can enter this division part in my pipeline. Do you have any idea?
>
> Regards,
>
> Josiane.
>
>
>
>
>
> typedef float PixelType;
>
> typedef itk::Image< PixelType, 3 > ImageType;
>
> typedef itk::ImageFileReader< ImageType > ReaderType;
>
> typedef itk::ImageFileWriter< ImageType > WriterType;
>
> ReaderType::Pointer reader1 = ReaderType::New();
>
> ReaderType::Pointer reader2 = ReaderType::New();
>
> ReaderType::Pointer reader3 = ReaderType::New();
>
> WriterType::Pointer writer = WriterType::New();
>
> reader1->SetFileName( argv[1] );
>
> reader2->SetFileName( argv[2] );
>
> reader3->SetFileName( argv[3] );
>
> writer->SetFileName( argv[4] );
>
> reader1->Update();
>
> reader2->Update();
>
> reader3->Update();
>
>
>
> typedef itk::AddImageFilter<
>
> ImageType,
>
> ImageType,
>
> ImageType > AdditionFilterType;
>
> AdditionFilterType::Pointer addition1 = AdditionFilterType::New();
>
> AdditionFilterType::Pointer addition2 = AdditionFilterType::New();
>
> addition1->SetInput1( reader1->GetOutput() );
>
> addition1->SetInput2( reader2->GetOutput() );
>
> addition2->SetInput1( reader3->GetOutput() );
>
> addition2->SetInput2( addition1->GetOutput() );
>
> writer->SetFileName( argv[4] );
>
> writer->SetInput( addition2->GetOutput()/3.0 );// I would like here to compute the mean between the three images
>
> writer->Update();
>
> return EXIT_SUCCESS;
>
>
> ________________________________
>
> De: Cameron Burnett [mailto:w_e_b_m_a_s_t_e_r_6_9 at hotmail.com]
> Date: lun. 26/05/2008 17:18
> À: Yankam Njiwa Josiane Adrienne
> Cc: insight-users at itk.org
> Objet : RE: [Insight-users] Mean image
>
>
> I'm not sure what the 'red' line is because I can't see any colour. Maybe the problem is that you haven't called Update() on your pipeline.
>
> reader1 > addition1 > addition2 > Image
> reader2 > addition1 > addition2 > Image
> reader3 > addition2 > Image
>
> Plugging in GetOutput() will set the links like above. EG: Reader3 goes to addition2 then to Image. If you do an Image->Update() then that will update everything thats linked to Image that is before it (all the links I typed above). Then you can actually use the image :).
>
> What are you doing on this line? ImageType::Pointer Image1 =Image/3.0;
> It seems like you're dividing the pointer by 3, and I'm fairly sure you don't want to do that. Maybe ImageType::Pointer Image1 =Image->GetOutput()/3.0;  might do something?? In that case I think writer->Update() WILL update your whole pipeline, and that previous problem will be fixed also.
>
>
>
>
>
> ________________________________
>
>> Date: Mon, 26 May 2008 17:01:33 +0200
>> From: njiwa at biomed.ee.ethz.ch
>> To: insight-users at itk.org
>> Subject: [Insight-users] Mean image
>>
>>
>>
>> Dear all,
>>
>> I would like to compute the mean between 3 images. I used the code bollow but the line in red seems to be false and i don't understand why. Could somebody help me please?
>>
>> Regards,
>>
>> Josiane.
>>
>>
>>
>>
>>
>> typedef itk::AddImageFilter<
>>
>> ImageType,
>>
>> ImageType,
>>
>> ImageType > AdditionFilterType;
>>
>> AdditionFilterType::Pointer addition1 = AdditionFilterType::New();
>>
>> AdditionFilterType::Pointer addition2 = AdditionFilterType::New();
>>
>> addition1->SetInput1( reader1->GetOutput() );
>>
>> addition1->SetInput2( reader2->GetOutput() );
>>
>> addition2->SetInput1( reader3->GetOutput() );
>>
>> addition2->SetInput2( addition1->GetOutput() );
>>
>> ImageType::Pointer Image = addition2->GetOutput();
>>
>> ImageType::Pointer Image1 =Image/3.0;
>>
>> writer->SetFileName( argv[4] );
>>
>> writer->SetInput( Image1 );
>>
>> writer->Update();
>>
>> _______________________________________________
>> Insight-users mailing list
>> Insight-users at itk.org
>> http://www.itk.org/mailman/listinfo/insight-users
>
>
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>
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