如何压缩图像的存储大小

Question

大家好:
    我抓拍了一幅视频图像并把它存成.bmp格式的文件，但占硬盘空间为663k，有没有更好的办法把生成的图像文件存储得更小一点。    我生成.bmp图像文件的程序如下
procedure TForm1.Button2Click(Sender: TObject);
var filename:string;
begin
   datetimetostring(filename,'yyyymmddhhmmss',now);
   filename:='d:\dvc\Record\'+filename+'.jpg';
   dvc1.CaptureToClipBoard;
   sleep(200);
   application.ProcessMessages;
   Image1.Picture.Assign(Clipboard);
   image1.Stretch:=true;
   image1.Picture.SaveToFile(filename);
end;    我急需这个功能，请大家详细指导，谢谢！

Answer 1

procedure Compress(var CompressedStream: TMemoryStream);
var
  SourceStream: TCompressionStream;
  DestStream: TMemoryStream;
  Count: Integer;
begin
  Count := CompressedStream.Size;
  DestStream := TMemoryStream.Create;
  SourceStream := TCompressionStream.Create(clMax, DestStream);
  try
    CompressedStream.SaveToStream(SourceStream);
    SourceStream.Free;
    CompressedStream.Clear;
    CompressedStream.WriteBuffer(Count, SizeOf(Count));
    CompressedStream.CopyFrom(DestStream, 0);
  finally
    DestStream.Free;
  end;
end;---------------------
      MemStream := TMemoryStream.Create;
      try
        MemStream.LoadFromFile(filename);
        MemStream.Seek(0, soFromBeginning);
        Compress(MemStream);
        MemStream.SaveToFile(Filename);
      finally
        MenStream.free;
      end;