OpenCV(4.5.5) 错误：cv::dnn::dnn4_v20211220::Net::forward C++ 中断言失败 (!empty())

Question

我最近创建了自己的 TensorFlow 对象检测模型。当我将模型加载到 OpenCV 的 DNN 中时，它在 net.forward() 处出现错误。我不知道是模型训练不当还是我设置的 DNN 模型不正确。

我尝试过其他模型，例如咖啡模型，这似乎有效。

代码 ：

#include <iostream>
#include <fstream>
#include <opencv2/opencv.hpp>
#include <opencv2/dnn.hpp>
#include <opencv2/dnn/all_layers.hpp>
 
using namespace std;
using namespace cv;
using namespace dnn;
 
 
int main(int, char**) {

    string file_path = "C:/Users/Daniel/source/repos/AR PROJECT/AR PROJECT/TF/";
    vector<string> class_names;
    ifstream ifs(string(file_path + "class.txt").c_str());
    string line;

    // Load in all the classes from the file
    while (getline(ifs, line))
    {   
        cout << line << endl;
        class_names.push_back(line);
    } 
    

    // Read in the neural network from the files
    auto net = readNetFromTensorflow("F:/models-master/research/object_detection/output_inference_graph/frozen_inference_graph.pb",
        "F:/models-master/research/object_detection/training/object-detection.pbtxt");
 

    // Open up the webcam
    VideoCapture cap(1);
 

    // Run on either CPU or GPU
    net.setPreferableBackend(DNN_BACKEND_CUDA);
    net.setPreferableTarget(DNN_TARGET_CUDA_FP16);


    // Set a min confidence score for the detections
    float min_confidence_score = 0.5;


    // Loop running as long as webcam is open and "q" is not pressed
    while (cap.isOpened()) {

        // Load in an image
        Mat image;
        bool isSuccess = cap.read(image);

        // Check if image is loaded in correctly
        if (!isSuccess){
            cout << "Could not load the image!" << endl;
            break;
        }
        
        int image_height = image.cols;
        int image_width = image.rows;

        auto start = getTickCount();

        // Create a blob from the image
        Mat blob = blobFromImage(image, 1.0, Size(300, 300));

        
        // Set the blob to be input to the neural network
        net.setInput(blob);

        // Forward pass of the blob through the neural network to get the predictions
        Mat output = net.forward();

        auto end = getTickCount();

        // Matrix with all the detections
        Mat results(output.size[2], output.size[3], CV_32F, output.ptr<float>());
        
        imshow("image", image);


        int k = waitKey(10);
        if (k == 113){
            break;
        }
    }
    
    cap.release();
    destroyAllWindows();
}

Answer 1

我通过将tensorflow SavedModel 转换为.onnx 使其工作。

这对我有用：

pip install tf2onnx

python -m tf2onnx.convert --saved-model tensorflow-model-path --opset 11 --output model.onnx

--saved-model：是保存模型的文件夹而不是 .pb 文件。

--opset 参数是可选的，但是对于我使用 opencv 4.6 来说，版本 11 工作正常，而版本 15> 则工作正常。没有。

在opencv-python中：

model = cv.dnn.readNetFromONNX("model.onnx")

https://github.com/onnx/tensorflow-onnx