PaddleX可视化客户端使用问题

[Zengfanxu1111]

Checklist:

1. 查找历史相关issue寻求解答
2. 翻阅FAQ常见问题汇总和答疑
3. 确认bug是否在新版本里还未修复
4. 如果bug是由PaddleX API 2.0导致，且该bug在develop分支里已修复，参考FAQ Q4替换内置PaddleX API

描述问题

运行示例任务时训练报错，但是未直接中断
项目为目标检测的昆虫项目

复现

1. 请提供您出现的报错信息及相关log（log的查找见 FAQ Q2）
   2.报错信息如下
   E:\PaddleX_GUI_2.1.0_win10\paddle\tensor\creation.py:130: DeprecationWarning: np.object is a deprecated alias for the builtin object. To silence this warning, use object by itself. Doing this will not modify any behavior and is safe.
   Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
   if data.dtype == np.object:
   Exception in thread Thread-5:
   Traceback (most recent call last):
   File "threading.py", line 917, in _bootstrap_inner
   File "threading.py", line 865, in run
   File "E:\PaddleX_GUI_2.1.0_win10\paddle\fluid\dataloader\dataloader_iter.py", line 213, in _thread_loop
   self._thread_done_event)
   File "E:\PaddleX_GUI_2.1.0_win10\paddle\fluid\dataloader\fetcher.py", line 121, in fetch
   data.append(self.dataset[idx])
   File "E:\PaddleX_GUI_2.1.0_win10\paddlex\cv\datasets\voc.py", line 324, in getitem
   sample = self.transforms(sample)
   File "E:\PaddleX_GUI_2.1.0_win10\paddlex\cv\transforms\operators.py", line 119, in call
   sample = self.decode_image(sample)
   File "E:\PaddleX_GUI_2.1.0_win10\paddlex\cv\transforms\operators.py", line 82, in call
   sample = self.apply(sample)
   File "E:\PaddleX_GUI_2.1.0_win10\paddlex\cv\transforms\operators.py", line 189, in apply
   sample['image'] = self.apply_im(sample['image'])
   File "E:\PaddleX_GUI_2.1.0_win10\paddlex\cv\transforms\operators.py", line 164, in apply_im
   image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
   cv2.error: OpenCV(4.1.2) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

2. 请提供您使用的GUI版本号
   3.2.1

3. 请提供您使用的操作系统信息，如Linux/Windows/MacOS
   windows10

4. 请问您使用的CUDA/cuDNN的版本号是？
   cuda11.2
   CuDnn 8.1.0