Ошибка - исключение класса EFOpenError с сообщением Cannot open file

unit Prg_17_1_;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Buttons, ExtCtrls, jpeg, ComCtrls;
type
TForm1 = class(TForm)
Image1: TImage;
Image2: TImage;
Label1: TLabel;
Label2: TLabel;
TrackBar1: TTrackBar;
Label3: TLabel;
Label4: TLabel;
Label5: TLabel;
    Label6: TLabel;
procedure BitBtn1Click(Sender: TObject);
procedure BitBtn2Click(Sender: TObject);
procedure TrackBar1Change(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
MyJpeg:TJpegImage;
MyBitMap:TBitmap;
MyMemory:TmemoryStream;
s1,s2,s3,s:string;
size:integer;
implementation
{$R *.dfm}
procedure TForm1.BitBtn1Click(Sender: TObject);
begin
Image1.Picture.Assign(MyBitmap);
MyMemory.Clear;
Mymemory.LoadFromFile(s1);
str(MyMemory.Size,s3);
Label1.Caption:=s3;
end;
procedure TForm1.BitBtn2Click(Sender: TObject);
begin
MyJpeg.Assign(MyBitmap);
MyJpeg.CompressionQuality:=100;
 
MyJpeg.Compress;
MyJpeg.SaveToFile(s2);
Image2.Picture.LoadFromFile(s2);
MyMemory.Clear;
Mymemory.LoadFromFile(s2);
str(MyMemory.Size,s3);
Label2.Caption:=s3;
end;
procedure TForm1.TrackBar1Change(Sender: TObject);
begin
str(TrackBar1.Min,s3);
Label3.Caption:=s3;
str(TrackBar1.Max,s3);
Label4.Caption:=s3;
str(TrackBar1.Position,s3);
Label5.Caption:=s3;
MyJpeg.CompressionQuality:=TrackBar1.Position;
MyJpeg.Compress;
MyJpeg.SaveToFile(s2);
Image2.Picture.LoadFromFile(s2);
MyMemory.Clear;
Mymemory.LoadFromFile(s2);
str(MyMemory.Size,s3);
Label2.Caption:=s3;
end;
initialization
    MyBitmap:=TBitMap.Create;
MyBitmap.LoadFromFile(s1);
s1:='Picture.bmp';
s2:='Picture.jpeg';
 
MyMemory:=TmemoryStream.Create;
MyJpeg:=TJpegImage.Create;
end.