ITK  5.0.0
Insight Segmentation and Registration Toolkit
Examples/SpatialObjects/ImageSpatialObject.cxx
/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
// Software Guide : BeginLatex
//
// \index{itk::ImageSpatialObject}
//
// An \doxygen{ImageSpatialObject} contains an \doxygen{Image} but adds the
// notion of spatial transformations and parent-child hierarchy. Let's begin
// the next example by including the appropriate header file.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
int main( int , char *[] )
{
// Software Guide : BeginLatex
//
// We first create a simple 2D image of size 10 by 10 pixels.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using Image = itk::Image<short,2>;
Image::Pointer image = Image::New();
Image::SizeType size = {{ 10, 10 }};
region.SetSize(size);
image->SetRegions(region);
image->Allocate();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Next we fill the image with increasing values.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
Iterator it(image,region);
short pixelValue =0;
for(it.GoToBegin(); !it.IsAtEnd(); ++it, ++pixelValue)
{
it.Set(pixelValue);
}
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We can now define the ImageSpatialObject which is templated over the dimension
// and the pixel type of the image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using ImageSpatialObject = itk::ImageSpatialObject<2,short>;
ImageSpatialObject::Pointer imageSO = ImageSpatialObject::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Then we set the itkImage to the ImageSpatialObject by using the
// \code{SetImage()} function.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
imageSO->SetImage(image);
imageSO->Update();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// At this point we can use \code{IsInside()}, \code{ValueAt()} and
// \code{DerivativeAt()} functions inherent in SpatialObjects. The
// \code{IsInside()} value can be useful when dealing with registration.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using Point = itk::Point<double,2>;
Point insidePoint;
insidePoint.Fill(9);
if( imageSO->IsInsideInWorldSpace(insidePoint) )
{
std::cout << insidePoint << " is inside the image." << std::endl;
}
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The \code{ValueAtInWorldSpace()} returns the value of the closest pixel,
// i.e no interpolation, to a given physical point.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
double returnedValue;
imageSO->ValueAtInWorldSpace(insidePoint,returnedValue);
std::cout << "ValueAt(" << insidePoint << ") = " << returnedValue
<< std::endl;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The derivative at a specified position in space can be computed using the
// \code{DerivativeAt()} function. The first argument is the point in
// physical coordinates where we are evaluating the derivatives. The second
// argument is the order of the derivation, and the third argument is the
// result expressed as a \doxygen{Vector}. Derivatives are computed
// iteratively using finite differences and, like the \code{ValueAt()}, no
// interpolator is used.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ImageSpatialObject::DerivativeVectorType returnedDerivative;
imageSO->DerivativeAtInWorldSpace(insidePoint,1,returnedDerivative);
std::cout << "First derivative at " << insidePoint;
std::cout << " = " << returnedDerivative << std::endl;
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}