procedure PrintPreviewDialog(aBitmap: Graphics.TBitmap; const DialogType: TIEDialogType = iedtDialog; const PrintSize: TIOPrintPreviewSize = psFitToPage);
var
  ImageEnView: TImageEnView;
begin
  ImageEnView := TImageEnView.Create(Nil);
  ImageEnView.IEBitmap.Assign(aBitmap);
  ImageEnView.IO.DialogsMeasureUnit := ieduCm;    // Centimeters
  ImageEnView.IO.PrintPreviewParams.Gamma := 0;
  // Specify print size :
  //ImageEnView.IO.PrintPreviewParams.Width := 800;
  //ImageEnView.IO.PrintPreviewParams.Height := 600;

  // Margins :
  ImageEnView.IO.PrintPreviewParams.MarginTop := 0.5;
  ImageEnView.IO.PrintPreviewParams.MarginLeft := 0.5;
  ImageEnView.IO.PrintPreviewParams.MarginRight := 0.5;
  ImageEnView.IO.PrintPreviewParams.MarginBottom := 0.5;

  // Fit/Stretch/Normal etc ...
  ImageEnView.IO.PrintPreviewParams.Size := PrintSize;

  ImageEnView.IO.DoPrintPreviewDialog(DialogType, 'Imprimir imagem', false, 'Imprimir ...');
  ImageEnView.Free;
end;