如何将BMP文件转换为JPG文件

将BMP文件转换为JPG文件，并保存

procedure BMPTOJpg(wj:string);

      var bmp:tbitmap;jpg:TJPEGImage;ms:tmemorystream;
begin
         bmp:=tbitmap.Create;
         bmp.LoadFromFile(wj);
         jpg:=TJPEGImage.Create;
         Jpg.Assign(bmp);
         ms:=tmemorystream.Create;
         Jpg.SaveToStream(MS);
          jpg.SaveToFile(changefileext(wj,'.jpg'));
end;