unit Unit1;

interface

uses 

  Windows, Messages, SysUtils, Classes, Graphics, Controls,     

  Forms, Dialogs,jpeg, ExtCtrls, StdCtrls,ActiveX, AxCtrls; 

type 

  TForm1 = class(TForm) 

    Image1: TImage; 

    Button2: TButton; 

    Image2: TImage; 

    procedure Button2Click(Sender: TObject); 

  private 

    procedure StreamToVariant(Stream: TMemoryStream; 

                              var v:  OleVariant); 

    procedure VariantToStream(const v: olevariant; 

                              Stream: TMemoryStream); 

    procedure JPEGToVariant(aJPEG : TJPEGImage; 

                             var aVariant:OleVariant); 

    procedure VariantToJPEG(aValue : OleVariant; 

                             var aJPEG:TJPEGImage); 

    { Private-Deklarationen } 

  public 

    { Public-Deklarationen } 

  end;

var 

  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.VariantToStream (const v : olevariant; Stream : TMemoryStream); 

var 

  p : pointer; 

begin 

  Stream.Position := 0; 

  Stream.Size := VarArrayHighBound (v, 1) - VarArrayLowBound (v, 1) + 1; 

  p := VarArrayLock (v); 

  Stream.Write (p^, Stream.Size); 

  VarArrayUnlock (v); 

  Stream.Position := 0; 

end;

procedure TForm1.StreamToVariant (Stream : TMemoryStream; var v : OleVariant); 

var 

  p : pointer; 

begin 

  v := VarArrayCreate ([0, Stream.Size - 1], varByte); 

  p := VarArrayLock (v); 

  Stream.Position := 0; 

  Stream.Read (p^, Stream.Size); 

  VarArrayUnlock (v); 

end;

procedure TForm1.JPEGToVariant(aJPEG : TJPEGImage; var aVariant:OleVariant); 

var 

  Stream        : TMemoryStream; 

begin 

    try 

      Stream := TMemoryStream.Create;

      aJPEG.Assign(Image1.Picture.Bitmap); 

      aJPEG.SaveToStream(Stream);

      StreamToVariant(Stream, aVariant); 

    finally 

       Stream.Free; 

   end; 

end;

procedure TForm1.VariantToJPEG(aValue : OleVariant;var aJPEG:TJPEGImage); 

var 

   Stream : TMemoryStream; 

begin 

try 

  Stream := TMemoryStream.Create;

  VariantToStream (aValue,Stream); 

  aJPEG.LoadfromStream(Stream);

finally 

   VariantClear(aValue); 

   Stream.free; 

end; 

end;

procedure TForm1.Button2Click(Sender: TObject); 

var 

   aJPEG :TJPEGImage; 

   aVariant : OleVariant; 

begin 

try 

   aJPEG:=TJPEGImage.Create;

   //JPEG To Variant 

   aJPEG.Assign(Image1.Picture.Bitmap); 

   JPEGToVariant(aJPEG,aVariant);

   //Variant To JPEG 

   VariantToJPEG(aVariant,aJPEG); 

   Image2.Picture.assign(aJPEG); 

finally 

   aJPEG.free; 

end; 

end;

end.