调用大图片时出现Stream read error和out of memory错误（急，在线等待）

做了一个报刊排版软件，要把几个4-5M的JPG文件同时调入报表中打印时出错，但此错误是随机出现的，不知有什么办法优化代码：贴部分代码如下：
procedure Tone_fourmodernmakeuppreviewForm.SpeedButton2Click(
  Sender: TObject);
  Var
    MS:TMemoryStream;
    Ajpeg:TJPEGImage;
begin
    if FileExists(FileNameLabel1.Caption) then
     begin
         MS:=TMemoryStream.Create;
         Ajpeg:=TJPEGImage.Create;
         try
           MS.LoadFromFile(FileNameLabel1.Caption);
           MS.Position:=0;
           Ajpeg.LoadFromStream(MS);
           one_fourpagekindpicturedisplayform.QRImage1.Picture.Assign(Ajpeg);
          finally
           MS.Free;
           Ajpeg.Free;
         end;
      end
    else
    one_fourpagekindpicturedisplayform.QRImage1.Picture:=nil;
    if FileExists(FileNameLabel2.Caption) then
     begin
         MS:=TMemoryStream.Create;
         Ajpeg:=TJPEGImage.Create;
         try
           MS.LoadFromFile(FileNameLabel2.Caption);
           MS.Position:=0;
           Ajpeg.LoadFromStream(MS);
           one_fourpagekindpicturedisplayform.QRImage2.Picture.Assign(Ajpeg);
          finally
           MS.Free;
           Ajpeg.Free;
         end;
      end
    else
    one_fourpagekindpicturedisplayform.QRImage2.Picture:=nil;
    if FileExists(FileNameLabel3.Caption) then
     begin
         MS:=TMemoryStream.Create;
         Ajpeg:=TJPEGImage.Create;
         try
           MS.LoadFromFile(FileNameLabel3.Caption);
           MS.Position:=0;
           Ajpeg.LoadFromStream(MS);
           one_fourpagekindpicturedisplayform.QRImage3.Picture.Assign(Ajpeg);
          finally
           MS.Free;
           Ajpeg.Free;
         end;
      end
    else
    one_fourpagekindpicturedisplayform.QRImage3.Picture:=nil;
    if FileExists(FileNameLabel4.Caption) then
     begin
         MS:=TMemoryStream.Create;
         Ajpeg:=TJPEGImage.Create;
         try
           MS.LoadFromFile(FileNameLabel4.Caption);
           MS.Position:=0;
           Ajpeg.LoadFromStream(MS);
           one_fourpagekindpicturedisplayform.QRImage4.Picture.Assign(Ajpeg);
          finally
           MS.Free;
           Ajpeg.Free;
         end;
      end
    else
    one_fourpagekindpicturedisplayform.QRImage4.Picture:=nil;
    one_fourpagekindpicturedisplayform.QRLabel1.Caption:='第'+PageNoLabel.Caption+'页';
    one_fourpagekindpicturedisplayform.QuickRep1.Prepare;
    one_fourpagekindpicturedisplayform.QuickRep1.Preview;
end;