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Using two dnn networks causes crash [closed]

asked 2018-11-07 00:47:03 -0500

pouya.1991 gravatar image

updated 2018-11-07 01:24:22 -0500

Hi I wanna to using two yolo networks in my program (an yolo3-tiny and an yolov3-spp), but when I call net.forward function for the second network, I'm got following exception :

terminate called after throwing an instance of 'cv::Exception'
what():  OpenCV(4.0.0-pre) /home/pouya/Develop/opecv4/opencv/modules/dnn/src/dnn.cpp:1149: error: (-204:Requested object was not found) Layer with requested id=-1 not found in function 'getLayerData'

there is my code :

bool Detector::postprocesstiny(const std::vector<cv::Mat>& outs)

    for (size_t i = 0; i < outs.size(); ++i)
        float* data = (float*)outs[i].data;
        for (int j = 0; j < outs[i].rows; ++j, data += outs[i].cols)
            cv::Mat scores = outs[i].row(j).colRange(5, outs[i].cols);
            cv::Point classIdPoint;
            double confidence;
            minMaxLoc(scores, 0, &confidence, 0, &classIdPoint);

            if (classIdPoint.x==2 && confidence > 0.5)
                return true ;

    return false ;


std::vector<cv::String> Detector::getOutputsNames(const cv::dnn::Net& net)
    static std::vector<cv::String> names;
    if (names.empty())
        std::vector<int> outLayers = net.getUnconnectedOutLayers();
        std::vector<cv::String> layersNames = net.getLayerNames();
        for (size_t i = 0; i < outLayers.size(); ++i)
            names[i] = layersNames[outLayers[i] - 1];
    return names;

bool Detector::isThereAnyCar(cv::Mat image) {

cv::Mat inputBlob = cv::dnn::blobFromImage(image, 1 / 255.F , cv::Size(416, 416), cv::Scalar(), true, false); 
std::vector<cv::Mat> outs;

net_tiny.forward(outs, getOutputsNames(net_tiny));  
return postprocesstiny(outs);


cv::dnn::Net net = cv::dnn::readNetFromDarknet(modelConfiguration, modelBinary);
cv::dnn::Net net_tiny = cv::dnn::readNetFromDarknet(modelConfigurationTiny, modelBinaryTiny);
cv::Mat frame;
cv::VideoCapture cap(source);
cap >> frame;
if (isThereAnyCar(frame)) {
        cv::Mat inputBlob = cv::dnn::blobFromImage(frame, 1 / 255.F , cv::Size(416, 416), cv::Scalar(), true, false); 
        std::vector<cv::Mat> outs;

        std::vector<DetectionResult> detection_results;
        net.forward(outs, getOutputsNames(net));  //This line causes error 


and when I comment one of the networks, it runs without any problem. Is there any solution for this problem?

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Closed for the following reason the question is answered, right answer was accepted by dkurt
close date 2018-11-08 05:47:43.459830



There is the configuration of this network :

pouya.1991 gravatar imagepouya.1991 ( 2018-11-07 00:54:41 -0500 )edit

so, the problem is NOT running 2 networks, but that there is something unsupported in the (new) ssp model, right ?

(if you thing it has to do with 2 networks, the, ofc. we need to see your code !)

berak gravatar imageberak ( 2018-11-07 00:56:41 -0500 )edit

No I can run the ssp model without any problem, but when I want to run two networks to gather I get this error

pouya.1991 gravatar imagepouya.1991 ( 2018-11-07 00:59:06 -0500 )edit

thank you, just added :) the last line causes error but when I comment if (isThereAnyCar(frame)) or net.forward(outs, getOutputsNames(net)) there is no error

pouya.1991 gravatar imagepouya.1991 ( 2018-11-07 01:26:53 -0500 )edit

i can only guess now, but the tiny-yolo is v2, and the ssp one v3, right ? imho, you cannot reuse the outs Mat vector for both of them, and they will have different outnames, too.

i also guess, if you change the order, you get an error in the other network ;)

berak gravatar imageberak ( 2018-11-07 01:32:08 -0500 )edit

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answered 2018-11-07 01:51:29 -0500

pouya.1991 gravatar image

Both of them are v3, thank you I just omit if (names.empty()) in getOutputsNames and the error vanished :)

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Asked: 2018-11-07 00:47:03 -0500

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Last updated: Nov 07