TIEMultiBitmap.IsVirtual

Declaration

property IsVirtual: Boolean;

Description

Specifies the object does not contain actual images, but is an array of indexed references.
In IsVirtual mode, the number of images in the TIEMultiBitmap is specified by VirtualCount.
The content of each TIEMultiBitmap frame is specified by OnGetVirtual.

Example

// Create a 100-frame TIFF file, where each frame shows its index
mbmp := TIEMultiBitmap.Create();
mbmp.OnGetVirtual := GetVirtualImage;
mbmp.VirtualCount := 100;
mbmp.IsVirtual    := True;
mbmp.SaveToFile( 'D:\NumberedTIFF.tiff' );
mbmp.Free;

// Event to supply each virtual frame
procedure TMainForm.GetVirtualImage(Sender: TObject; idx: integer; var Width, Height: Integer; Image: TIEBitmap; Params: TIOParams);
const
  Image_Width = 800;
  Image_Height = 600;
var
  proc: TImageEnProc;
begin
  // Seeking bitmap?
  if Image <> nil then
  begin
    // Create our bitmap for image idx

    // Allocate size and fill with background color
    Image.Allocate( Image_Width, Image_Height, clYellow );

    // Draw text (image number)
    proc := TImageEnProc.CreateFromBitmap( Image );
    proc.TextOut( Align_Text_Horz_Center, Align_Text_Vert_Center, IntToStr( idx ), 'Arial', 128, clRed, [fsBold]);
    proc.Free;
  end
  else
  // Seek IO Parameters?
  if Params <> nil then
  begin
    // Specify the image properties of image idx
    Params.TIFF_Compression := ioTIFF_JPEG;
    Params.TIFF_JPEGQuality := 85;
  end
  else
  // Image Dimensions
  if Params <> nil then
  begin
    // Specify the size of image idx
    Width := Image_Width;
    Height := Image_Height;
  end;
end;

// Displaying a virtual multi-bitmap in a TImageEnMView
TIEMultiBitmap( ImageEnMView1.IEMBitmap ).OnGetVirtual := GetVirtualImage;
TIEMultiBitmap( ImageEnMView1.IEMBitmap ).VirtualCount := 10000;
TIEMultiBitmap( ImageEnMView1.IEMBitmap ).IsVirtual    := True;

TIEMultiBitmap.IsVirtual