procedure SaveAsJPG ;

var

  jp: TJPEGImage;  //Requires the “jpeg” unit added to “uses” clause.

begin

  jp := TJPEGImage.Create;

  try

    with jp do

    begin

      jp.CompressionQuality := 2;

      jp.Compress ;  

      Assign(Image1.Picture.Bitmap);

      SaveToFile(D:\zhy.jpg);

    end;

  finally

    jp.Free;

  end;

  ////—读入方法如下:

procedure OpenJPGInImage

var

  jp: TJPEGImage;  //Requires the “jpeg” unit added to “uses” clause.

begin

  jp := TJPEGImage.Create;

  jp.LoadFromFile(D:\zhy.jpg);

  try

    with jp do

    begin

      image1.Picture.Bitmap.Assign(jp);

    end;

  finally

    jp.Free;

  end;

end;