Method RequestData

IO/Image/vtkNIFTIImageWriter.cxx:581–948

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//------------------------------------------------------------------------------
int vtkNIFTIImageWriter::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* vtkNotUsed(outputVector))
{
  this->SetErrorCode(vtkErrorCode::NoError);

  vtkInformation* info = inputVector[0]->GetInformationObject(0);
  vtkImageData* data = vtkImageData::SafeDownCast(info->Get(vtkDataObject::DATA_OBJECT()));

  if (data == nullptr)
  {
    vtkErrorMacro("No input provided!");
    return 0;
  }

  const char* filename = this->GetFileName();
  if (filename == nullptr)
  {
    vtkErrorMacro("A FileName must be provided");
    this->SetErrorCode(vtkErrorCode::NoFileNameError);
    return 0;
  }

  int extent[6];
  info->Get(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), extent);

  // use compression if name ends in .gz
  bool isCompressed = false;
  size_t n = strlen(filename);
  size_t m = n;
  if (n > 2 && filename[n - 3] == '.' && tolower(filename[n - 2]) == 'g' &&
    tolower(filename[n - 1]) == 'z')
  {
    m = n - 3;
    isCompressed = true;
  }

  // after the optional ".gz" is removed, is it a ".img/.hdr" file?
  bool singleFile = true;
  if (m > 4 && filename[m - 4] == '.' &&
    ((tolower(filename[m - 3]) == 'h' && tolower(filename[m - 2]) == 'd' &&
       tolower(filename[m - 1]) == 'r') ||
      (tolower(filename[m - 3]) == 'i' && tolower(filename[m - 2]) == 'm' &&
        tolower(filename[m - 1]) == 'g')))
  {
    singleFile = false;
  }

  // generate the header information
  if (this->GenerateHeader(info, singleFile) == 0)
  {
    return 0;
  }

  // if file is not .nii, then get .hdr and .img filenames
  char* hdrname = vtkNIFTIImageWriter::ReplaceExtension(filename, ".img", ".hdr");
  char* imgname = vtkNIFTIImageWriter::ReplaceExtension(filename, ".hdr", ".img");

  vtkDebugMacro(<< "Writing NIFTI file " << hdrname);