!7105 set num threads for opencv

Merge pull request !7105 from yanghaitao/yht_set_num_threads_for_opencv

mindspore/ccsrc/minddata/dataset/kernels/image/image_utils.cc

@@ -97,6 +97,8 @@ Status Resize(const std::shared_ptr<Tensor> &input, std::shared_ptr<Tensor> *out
   if (input_cv->Rank() != 3 && input_cv->Rank() != 2) {
     RETURN_STATUS_UNEXPECTED("Input Tensor is not in shape of <H,W,C> or <H,W>");
   }
+  // OpenCv lanuch too many threads.
+  cv::setNumThreads(0);
   cv::Mat in_image = input_cv->mat();
   // resize image too large or too small
   if (output_height == 0 || output_height > in_image.rows * 1000 || output_width == 0 ||