public static void startPreview(previewFPS previewFPS)
 {
     IsCapturing = true;
     if (!previewRoutine.IsBusy)
     {
         previewRoutine.RunWorkerAsync(previewFPS);
         ImageProcessService.StartImgProcessRoutine();
     }
 }
 public static void StopPreview()
 {
     IsCapturing = false;
     previewRoutine.CancelAsync();
     ImageProcessService.StopImgProcessRoutine();
 }