如何使用 OpenVINO 预训练模型？

Question

I have installed OpenVINO recently but I don't know how I should give inputs and get the predict from OpenVINOs pre-trained models.

there is two files with .bin and .xml suffixes, I've just worked with keras so I can't use this models in opencv.

I find this code but it didn't work.

import cv2 as cv

net = cv.dnn.readNet('face-detection-adas-0001.bin', 'face-detection-adas-0001.xml')

cap = cv.VideoCapture(0)

while cv.waitKey(1) < 0:
    hasFrame, frame = cap.read()
    if not hasFrame:
        break

    blob = cv.dnn.blobFromImage(frame, size=(672, 384))
    net.setInput(blob)
    out = net.forward()

    for detection in out.reshape(-1, 7):
        confidence = float(detection[2])
        xmin = int(detection[3] * frame.shape[1])
        ymin = int(detection[4] * frame.shape[0])
        xmax = int(detection[5] * frame.shape[1])
        ymax = int(detection[6] * frame.shape[0])

        if confidence > 0.5:
            cv.rectangle(frame, (xmin, ymin), (xmax, ymax), color=(0, 255, 0))

    cv.imshow('OpenVINO face detection', frame)

there's the error code:

Traceback (most recent call last):
  File "C:\Users\Ali-10\Desktop\facial_landmark\face.py", line 3, in <module>
    net = cv.dnn.readNet('face-detection-adas-0001.bin', 'face-detection-adas-0001.xml')
    cv2.error: OpenCV(3.4.4) C:\projects\opencv-python\opencv\modules\dnn\src\dnn.cpp:2428: error: (-2:Unspecified error) Build OpenCV with Inference Engine to enable loading models from Model Optimizer. in function 'cv::dnn::experimental_dnn_34_v10::Net::readFromModelOptimizer'

I expect the prediction of the model but I just get this error.

Answer 1

I just tested this code and it works perfectly fine. You need to install openvino first and then run setupvars.bat file in order to initialize the openvino enviroment. Once that is done, you can run your code and it will start detecting your face. I tested this on Intel i5 with 12Gb RAM and I was getting 23-25fps which is good.

Answer 2

You need to build OpenCV with Inference Engine support as mentioned in the message. See wiki for details: https://github.com/opencv/opencv/wiki/Intel%27s-Deep-Learning-Inference-Engine-backend .

If you use OpenCV from OpenVINO distribution, it must be already built with IE (maybe except a single R5.1 release from January of 2019).

We also work on simplified way to build OpenCV with IE (without specifying paths but just downloading it's source code by cmake), see PR https://github.com/opencv/opencv/pull/13965 .