/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkImageFFT.h
  Language:  C++
  Date:      $Date$
  Version:   $Revision$
  Thanks:    Thanks to C. Charles Law who developed this class.

Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

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modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names
   of any contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

 * Modified source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/
// .NAME vtkImageFFT -  Fast Fourier Transform.
// .SECTION Description
// vtkImageFFT implements a  fast Fourier transform.  The input
// can have real or imaginary data in any components and data types, but
// the output is always float with real values in component0, and
// imaginary values in component1.  The filter is fastest for images that
// have power of two sizes.  Multi dimensional FFT's are decomposed so
// that each axis executes in series.


#ifndef __vtkImageFFT_h
#define __vtkImageFFT_h


#include "vtkImageFourierFilter.h"

class VTK_EXPORT vtkImageFFT : public vtkImageFourierFilter
{
public:
  static vtkImageFFT *New();
  vtkTypeMacro(vtkImageFFT,vtkImageFourierFilter);


  // Description:
  // Used internally for streaming and threads.  
  // Splits output update extent into num pieces.
  // This method needs to be called num times.  Results must not overlap for
  // consistent starting extent.  Subclass can override this method.
  // This method returns the number of pieces resulting from a
  // successful split.  This can be from 1 to "total".  
  // If 1 is returned, the extent cannot be split.
  int SplitExtent(int splitExt[6], int startExt[6], 
		  int num, int total);

protected:
  vtkImageFFT() {};
  ~vtkImageFFT() {};
  vtkImageFFT(const vtkImageFFT&) {};
  void operator=(const vtkImageFFT&) {};

  void ExecuteInformation(vtkImageData *inData, vtkImageData *outData);
  void ComputeInputUpdateExtent(int inExt[6], int outExt[6]);
  void ExecuteInformation(){this->vtkImageIterateFilter::ExecuteInformation();};
  void ThreadedExecute(vtkImageData *inData, vtkImageData *outData,
		       int outExt[6], int threadId);
};

#endif










