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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: Image3.cxx
Language: C++
Date: $Date$
Version: $Revision$
Copyright (c) Insight Software Consortium. All rights reserved.
See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#endif
// Software Guide : BeginLatex
//
// This example illustrates the use of the \code{SetPixel()} and
// \code{GetPixel()} methods. These two methods provide direct access to the
// pixel data contained in the image. Note that these two methods are
// relatively slow and should not be used in situations where
// high-performance access is required. Image iterators are the appropriate
// mechanism to efficiently access image pixel data. (See
// Chapter~\ref{sec:ImageIteratorsChapter} on page
// \pageref{sec:ImageIteratorsChapter} for information about image
// iterators.)
//
// Software Guide : EndLatex
#include "itkImage.h"
int main(int, char *[])
{
// First the image type should be declared
typedef itk::Image< unsigned short, 3 > ImageType;
// Then the image object can be created
ImageType::Pointer image = ImageType::New();
// The image region should be initialized
ImageType::IndexType start;
ImageType::SizeType size;
size[0] = 200; // size along X
size[1] = 200; // size along Y
size[2] = 200; // size along Z
start[0] = 0; // first index on X
start[1] = 0; // first index on Y
start[2] = 0; // first index on Z
ImageType::RegionType region;
region.SetSize( size );
region.SetIndex( start );
// Pixel data is allocated
image->SetRegions( region );
image->Allocate();
// The image buffer is initialized to a particular value
ImageType::PixelType initialValue = 0;
image->FillBuffer( initialValue );
// Software Guide : BeginLatex
//
// The individual position of a pixel inside the image is identified by a
// unique index. An index is an array of integers that defines the position
// of the pixel along each coordinate dimension of the image. The IndexType
// is automatically defined by the image and can be accessed using the
// scope operator like \doxygen{Index}. The length of the array will match
// the dimensions of the associated image.
//
// The following code illustrates the declaration of an index variable and
// the assignment of values to each of its components. Please note that
// \code{Index} does not use SmartPointers to access it. This is because
// \code{Index} is a light-weight object that is not intended to be shared
// between objects. It is more efficient to produce multiple copies of
// these small objects than to share them using the SmartPointer
// mechanism.
//
// The following lines declare an instance of the index type and initialize
// its content in order to associate it with a pixel position in the image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ImageType::IndexType pixelIndex;
pixelIndex[0] = 27; // x position
pixelIndex[1] = 29; // y position
pixelIndex[2] = 37; // z position
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Having defined a pixel position with an index, it is then possible to
// access the content of the pixel in the image. The \code{GetPixel()}
// method allows us to get the value of the pixels.
//
// \index{itk::Image!GetPixel()}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ImageType::PixelType pixelValue = image->GetPixel( pixelIndex );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The \code{SetPixel()} method allows us to set the value of the pixel.
//
// \index{itk::Image!SetPixel()}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
image->SetPixel( pixelIndex, pixelValue+1 );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Please note that \code{GetPixel()} returns the pixel value using copy
// and not reference semantics. Hence, the method cannot be used to
// modify image data values.
//
// Remember that both \code{SetPixel()} and \code{GetPixel()} are inefficient
// and should only be used for debugging or for supporting interactions like
// querying pixel values by clicking with the mouse.
//
// Software Guide : EndLatex
return 0;
}
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