小编Chi*_*ter的帖子

当我编译这个例子时:

#include <iostream>
#include "opencv2/opencv.hpp"
#include "opencv2/gpu/gpu.hpp"

int main (int argc, char* argv[])

{
    try
    {
        cv::Mat src_host = cv::imread("file.png", CV_LOAD_IMAGE_GRAYSCALE);
        cv::gpu::GpuMat dst, src;
        src.upload(src_host);

        cv::gpu::threshold(src, dst, 128.0, 255.0, CV_THRESH_BINARY);

        cv::Mat result_host = dst;
        cv::imshow("Result", result_host);
        cv::waitKey();
    }
    catch(const cv::Exception& ex)
    {
        std::cout << "Error: " << ex.what() << std::endl;
    }
    return 0;
}

我收到以下错误:

threshold.cpp: In function ‘int main(int, char**)’:
threshold.cpp:19: error: conversion from ‘cv::gpu::GpuMat’ to non-scalar type ‘cv::Mat’ requested

有人知道为什么吗？