openvino: [Bug] CPU inference bug in OpenVINO 2021.2.185

System information (version)

• OpenVINO=> 2021.2.185
• OpenCV => 4.5.1 (OpenVINO version)
• Qt => 5.12.2
• Operating System / Platform => Windows 10 Pro 64 Bit
• Compiler => Visual Studio 2019
• Problem classification => Inference with OpenCV (dnn module)

Detailed description

Hello everyone! I would like to develop a vehicles and license plates detector using the model vehicle-license-plate-detection-barrier-0106 (FP32). In my project I linked to the OpenCV libraries released with OpenVINO. Seems the dnn module is not working, my program crashes on the readNetFromModelOptimizer function without showing any message. I tried also with FP16 and INT8 of the same model. Changing readNetFromModelOptimizer(...) to readNet(...) does not solve the problem!

Steps to reproduce

#include <opencv2/dnn/dnn.hpp>
...code...
...code...
const std::string openvino_xml = "C:/Users/Franco/Documents/Intel/OpenVINO/openvino_models/ir/intel/vehicle-license-plate-detection-barrier-0106/FP32/vehicle-license-plate-detection-barrier-0106.xml";
const std::string openvino_bin = "C:/Users/Franco/Documents/Intel/OpenVINO/openvino_models/ir/intel/vehicle-license-plate-detection-barrier-0106/FP32/vehicle-license-plate-detection-barrier-0106.bin";

auto vehicleNet = cv::dnn::readNetFromModelOptimizer(openvino_xml, openvino_bin); //<-- this call freezes my program
vehicleNet.setPreferableBackend(cv::dnn::DNN_BACKEND_INFERENCE_ENGINE);
vehicleNet.setPreferableTarget(cv::dnn::DNN_TARGET_CPU);
...code...

Issue submission checklist

• I report the issue, it’s not a question
• I checked the problem with documentation, FAQ, open issues, Stack Overflow, etc and have not found solution
• There is reproducer code and related data files: images, videos, models, etc.