unit JPG_Image interface uses Classes jpeg type TJPG_Image class TJPEG

unit JPG_Image;

interface

uses Classes,jpeg;

   type
     TJPG_Image = class (TJPEGImage)
      private
         function GetRealSize(Stream: TStream):Integer;
       public
         procedure LoadFromStream(Stream: TStream);     //override;
     end;
implementation

{ TJPG_Image }
function sw2(x: Word): Word;
begin
  Result:=x and $ff;
  Result:=(Result shl 8)+((x shr 8) and $ff);
end;  

function TJPG_Image.GetRealSize(Stream: TStream): Integer;
var
  pos:Int64;
  w: Word;
begin
  Result:=0;
   pos:=Stream.Position;
   Stream.Read(w,2);
   if (w=$d8ff) then
   begin
     while (True)  do
     begin
        if Stream.Position>=Stream.Size-2 then Exit;
        Stream.Read(w,2);
        if w=$d9ff then Break;
        if Lo(w)=$ff then
        begin
          Stream.Read(w,2);
          w:=sw2(w);
          Stream.Position:=Stream.Position+w-2;
        end
        else
        Stream.Position:=Stream.Position-1;
     end;
     Result:=Stream.Position-pos;
   end;
end;

procedure TJPG_Image.LoadFromStream(Stream: TStream);
begin
   ReadStream(GetRealSize(Stream),Stream);
end;

end.