调用openalpr :: recognize导致段错误

Question

我有一个opencv图像缓冲区，我想传递给OpenALPR :: recognize（）（它接受图像路径或内存中的图像），但是出现分段错误，我似乎找不到问题。我编写了一个演示该问题的演示应用程序：

//compilation: g++ -Wall test.cpp -lopenalpr -lopencv_core -lopencv_imgproc -lopencv_highgui -o test
#include <alpr.h>
#include <iostream>
#include <fstream>
#include <sstream>
#include <ios>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>

int main (void) 
{
    std::string fname = "0000024867.jpg";
    std::ifstream is;
    std::ostringstream ss;
    alpr::Alpr openalpr("us", "/etc/openalpr/openalpr.conf");

    openalpr.setTopN(20);

    if (openalpr.isLoaded() == false)
    {
            std::cerr << "Error loading OpenALPR" << std::endl;
                return 1;
    }

    //is.open(fname.c_str(), std::ios::binary);
    //ss << is.rdbuf();
    const std::string& s = ss.str();
    cv::Mat image = cv::imread(fname.c_str(), CV_LOAD_IMAGE_COLOR);
    std::vector <unsigned char> buff;
    std::vector <int>param = std::vector<int>(2);
    param[0] = cv::IMWRITE_JPEG_QUALITY;
    param[1] = 70;
    imencode(".jpg",image,buff,param);

    std::vector<char> vec(buff.begin(), buff.end());

    alpr::AlprResults results = openalpr.recognize(vec);

    // Carefully observe the results. There may be multiple plates in an image,
    // and each plate returns the top N candidates.
    for (unsigned int i = 0; i < results.plates.size(); i++) {
        alpr::AlprPlateResult plate = results.plates[i];
        std::cout << "plate" << i << ": " << plate.topNPlates.size() << " results" << std::endl;

        for (unsigned int k = 0; k < plate.topNPlates.size(); k++) {
            alpr::AlprPlate candidate = plate.topNPlates[k];
            std::cout << "    - " << candidate.characters << "\t confidence: " <<
            candidate.overall_confidence << std::endl;
        }
    }

    return 0;
}

可以从此处下载图像：0000024867.jpg

发生了什么：在alpr::AlprResults results = openalpr.recognize(vec);行上抛出了段错误。
预期结果：.recognize()函数执行没有错误，并且代码继续循环遍历图像中找到的LP。