Как да заредя JPEG...

procedure TfmMain.ShowImage(ImageName:String; ImageStr:TMemoryStream; var Image:TImage);

var

  Graphic:TGraphic;

  ImageType:String;

begin

  if ImageStr.Size <= 1 then

    Exit;

  try

    ImageType := UPPERCase(ExtractFileExt(ImageName));

    if (ImageType = '.JPG') OR (ImageType = '.JPEG') then

      Graphic := TJpegImage.Create;

    ImageStr.Position := 0;

    Graphic.LoadFromStream(ImageStr);

    Image.Picture.Assign(Graphic);

  finally

    Graphic.Free;

  end;

end;