[Insight-users] Problems using Transforms and Filters
Luis Ibanez
luis.ibanez@kitware.com
Mon May 10 02:38:03 EDT 2004
Hi Rob,
The problem you have with the Threshold filter is
due to the fact that you are setting the Upper and
Lower thresholds to the same value.
> filter->SetLowerThreshold( 180 ); //
> filter->SetUpperThreshold( 180 ); //
> filter->Update(); //
The filter expects the
Upper > Lower
It checks for this relationship, and if it fails,
it throws and exception.
Since you didn't put the filter->Update() invokation
inside a try/catch block, you are not catching the
exception and the program is aborting.
Please read the description of this filter in the
ITK Software Guide, so you understand what it is
expected from the parameters.
Regards,
Luis
-----------------------
Rob Bijman wrote:
> Dear Luis and other ITK users,
>
> first of all I want to thank you for your help!
>
> The pictures I am registrating are indeed from a camera (digital camera
> from canon).
> For the multicolor images I shall try to use the solutions you gave me.
>
> For the problems I have with the Binary Treshold Filter (and other
> filters), I couldn't send an attachment in Word format with some program
> parameters, so I put it in the end of the e-mail The parameters used
> for the filter have been put inside "/" signs like:
>
> //////////////
> Filter Tekst
> //////////////
>
> Without using these parameters for the filter the program works without
> errors.
> The error I get when I push a button to registrate two pictures is:
> "Runtime Error, Program C:\.... , abnormal program termination".
> I hope that you can help me further with this. I woulb be very happy.
>
> With kind regards,
>
> Rob Bijman
>
>
>
>
>
>
>> From: Luis Ibanez <luis.ibanez@kitware.com>
>> To: Rob Bijman <lambikjes@hotmail.com>
>> CC: insight-users@itk.org
>> Subject: Re: [Insight-users] Problems using Transforms and Filters
>> Date: Tue, 04 May 2004 10:25:19 -0400
>>
>>
>> Hi Rob,
>>
>>
>> Welcome to ITK !,
>>
>>
>>
>> A) About multicolor images: I assume that you are using RGB or RGBA
>> images. Note that the image metrics available in ITK at this point
>> are for escalar images, that is, grayscale images or simply images
>> with a single component. We have performed registration of color
>> images by using the two following methods:
>>
>> A.1) Extracting one channel from the color image, for example the
>> red channed, and using it as a scalar image for performing
>> registration.
>>
>> A.2) Converting the color image into a grayscale image by computing
>> a linear combination of its color components.
>>
>> Both of this operations can be performed by creating a filter
>> that derives from the UnaryFunctorFitler or by using
>> ImageAdaptors. You will find a description on how to do this in
>> Chapter 12 of the software guide.
>>
>>
>> Of course, you could be more creative and do:
>>
>> A.3) Implement an image metric customized for color images. In that
>> case you should take a look at the actual code of the image to
>> image metrics in Insight/Code/Algorithms
>>
>>
>> BTW, why are you getting color images if you are working with
>> patients that are being X-rayed ?
>>
>> Are you using a video camera for taking an external view of the
>> patient ?
>>
>> If that's the case, you should rather look into using a motion
>> detection method such as the DemonsRegistration filter:
>>
>> http://www.itk.org/Insight/Doxygen/html/classitk_1_1DemonsRegistrationFilter.html
>>
>>
>> You should still convert your color images to grayscale, unless
>> you think that there are valuable information encoded in the color.
>>
>>
>>
>>
>>
>> B) We will be more than happy to help you with the problem
>> that you have when introducing the threshold filter in
>> your program. Unfortunately our divinatory capabilities
>> have been seriously deteriorated by excesive use. It will
>> therefore be very helpful if you could share with us some
>> interesting details of your code such as:
>>
>> C.1) The error messages that you get when your program fails.
>> C.2) The kind of processing that you are attempting to perform.
>> C.3) The mechanism that you used for passing your image to ITK.
>> C.4) An actual piece of code will be greatly appreciated.
>>
>>
>>
>> Best regards,
>>
>>
>> Luis
>>
>>
>> -----------------
>> Rob Bijman wrote:
>>
>>> Dear ITK users,
>>>
>>> I am working for the MST Hospital in the Netherlands and I am trying
>>> to use ITK for a registration process. It's my job to develop a
>>> program that notices movements of patients when they are being x-rayed.
>>> The problem is that the values I get from the transforms I use
>>> (Affine Transform / Translation Transform) do not match with the
>>> theoretical values when I use 'real' multicolor images. I used the
>>> ITK software guide and have put the transforms inside the program
>>> exactly the way it has been described. It only works when using
>>> example pictures from ITK 1.6.0, and the rotation from the Affine
>>> Transform doesn't work at all (very strange values). Does anyone have
>>> some extra documentation for me, or some help?
>>> The second problem is the use of filters. When I put filters (for
>>> example the binary tresholdfilter) into the program, like described
>>> in the ITK software guide, the program runs normally, but when I
>>> start the registration the program returns an error.
>>> It would be very nice if someone has got some extra information for
>>> this. I hope that what I described above is clear enough.
>>>
>>> With kind regards,
>>>
>>> Rob Bijman
>>> MST Enschede, Netherlands
>>>
>>
>>
>>
>> _______________________________________________
>> Insight-users mailing list
>> Insight-users@itk.org
>> http://www.itk.org/mailman/listinfo/insight-users
>
>
>
> ////////////////////////////////Binary Treshold Image
> Filter/////////////////////////////////////////////////////
> if (m_Eerste = TRUE)
> {
>
> const unsigned int Dimension = 2;
> typedef float PixelType;
> //////////////
> typedef unsigned char InputPixelType;
> typedef unsigned char OutputPixelType;
> typedef itk::Image< InputPixelType, 2 > InputImageType;
> ///////////
> typedef itk::Image< OutputPixelType, 2 > OutputImageType;
> ////////////
> typedef itk::Image< PixelType, Dimension > FixedImageType;
> typedef itk::Image< PixelType, Dimension > MovingImageType;
>
> typedef itk::TranslationTransform< double, Dimension >
> TransformType;
> typedef itk::RegularStepGradientDescentOptimizer
> OptimizerType;
> typedef itk::MattesMutualInformationImageToImageMetric<
> FixedImageType,
> MovingImageType > MetricType;
> typedef itk:: LinearInterpolateImageFunction<
> MovingImageType,
> double > InterpolatorType;
> typedef itk::ImageRegistrationMethod<
> FixedImageType,
> MovingImageType > RegistrationType;
>
> //////////////////////////////////////////////////////////////////////////////////
>
> typedef
> itk::BinaryThresholdImageFilter< //
> InputImageType, OutputImageType >
> FilterType; //
> typedef itk::ImageFileReader< InputImageType > ReaderType;
> typedef itk::ImageFileWriter< InputImageType > WriterType;
> //////////////////////////////////////////////////////////////////////////////////
>
> MetricType::Pointer metric = MetricType::New();
> TransformType::Pointer transform = TransformType::New();
> OptimizerType::Pointer optimizer = OptimizerType::New();
> InterpolatorType::Pointer interpolator = InterpolatorType::New();
> RegistrationType::Pointer registration = RegistrationType::New();
>
> ///////////////////////////////////////////////////
> ReaderType::Pointer reader = ReaderType::New();//
> FilterType::Pointer filter = FilterType::New();//
> ///////////////////////////////////////////////////
>
> registration->SetMetric( metric );
> registration->SetOptimizer( optimizer );
> registration->SetTransform( transform );
> registration->SetInterpolator( interpolator );
>
> typedef itk::ImageFileReader< FixedImageType > FixedImageReaderType;
> typedef itk::ImageFileReader< MovingImageType > MovingImageReaderType;
>
> FixedImageReaderType::Pointer fixedImageReader =
> FixedImageReaderType::New();
> MovingImageReaderType::Pointer movingImageReader =
> MovingImageReaderType::New();
>
> fixedImageReader->SetFileName( m_sRef );
> movingImageReader->SetFileName( m_sBew );
> UpdateData(FALSE);
>
> registration->SetFixedImage( fixedImageReader->GetOutput() );
> registration->SetMovingImage( movingImageReader->GetOutput() );
>
> fixedImageReader->Update();
> movingImageReader->Update();
>
> registration->SetFixedImageRegion(
> fixedImageReader->GetOutput()->GetBufferedRegion() );
>
> typedef RegistrationType::ParametersType ParametersType;
> ParametersType initialParameters( transform->GetNumberOfParameters() );
>
> initialParameters[0] = 0.0; // Initial offset in mm along X
> initialParameters[1] = 0.0; // Initial offset in mm along Y
>
> registration->SetInitialTransformParameters( initialParameters );
>
> ////////////////////////////////////////////
> filter->SetInput( reader->GetOutput() );//
> filter->SetOutsideValue(0); //
> filter->SetInsideValue(120); //
> filter->SetLowerThreshold( 180 ); //
> filter->SetUpperThreshold( 180 ); //
> filter->Update(); //
> ////////////////////////////////////////////
>
> optimizer->SetMaximumStepLength( 4.00 ); //4.00
> optimizer->SetMinimumStepLength( 0.001 ); //0.005
> optimizer->SetNumberOfIterations( 200 ); //200
>
> metric->SetNumberOfHistogramBins( 20 ); //20
> metric->SetNumberOfSpatialSamples( 10000 ); //10000
>
> try
> {
> registration->StartRegistration();
> }
> catch(...)
> {
> m_sTekst= "Dit gaat fout";
> }
>
>
> ParametersType finalParameters =
> registration->GetLastTransformParameters();
>
> const double TranslationAlongX = finalParameters[0];
>
> const double TranslationAlongY = finalParameters[1];
>
> const unsigned int numberOfIterations = 50;
> //optimizer->GetCurrentIteration();
>
> const double bestValue = optimizer->GetValue();
>
>
> //int m_dOpt;
> //int m_dNumIt;
> m_dTransX = TranslationAlongX;
> m_dTransY = TranslationAlongY;
> m_sTekst = "Bijstellen";
> //m_dOpt = 0;
> //m_dRot = 0;
> UpdateData(FALSE);
>
> _________________________________________________________________
> Hotmail en Messenger on the move
> http://www.msn.nl/communicatie/smsdiensten/hotmailsmsv2/
>
> _______________________________________________
> Insight-users mailing list
> Insight-users@itk.org
> http://www.itk.org/mailman/listinfo/insight-users
>
More information about the Insight-users
mailing list