visual-studio - opencv中的链接器问题

Question

我在 Visual Studio 2012 中使用 OpenCV 2.4.6，并且我测试了其中一个示例程序，名称为 matcher_simple.cpp——它匹配两个示例图像 image1 和 image2。

#include <stdio.h>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/nonfree/nonfree.hpp"
#include "opencv2/opencv.hpp"

using namespace cv;

static void help()
{
    printf("\nThis program demonstrates using features2d detector, descriptor extractor and simple matcher\n"
            "Using the SURF desriptor:\n"
            "\n"
            "Usage:\n matcher_simple <image1> <image2>\n");
}

int main(int argc, char** argv)
{
    if(argc != 3)
    {
        help();
        return -1;
    }

    //cv::initModule_nonfree();
    Mat img1 = imread(argv[1], CV_LOAD_IMAGE_GRAYSCALE);
    Mat img2 = imread(argv[2], CV_LOAD_IMAGE_GRAYSCALE);
    if(img1.empty() || img2.empty())
    {
        printf("Can't read one of the images\n");
        return -1;
    }


    // detecting keypoints
    SurfFeatureDetector detector(400);
    vector<KeyPoint> keypoints1, keypoints2;
    detector.detect(img1, keypoints1);
    detector.detect(img2, keypoints2);

    // computing descriptors
    SurfDescriptorExtractor extractor;
    Mat descriptors1, descriptors2;
    extractor.compute(img1, keypoints1, descriptors1);
    extractor.compute(img2, keypoints2, descriptors2);

    // matching descriptors
    BFMatcher matcher(NORM_L2);
    vector<DMatch> matches;
    matcher.match(descriptors1, descriptors2, matches);

    // drawing the results
    namedWindow("matches", 1);
    Mat img_matches;
    drawMatches(img1, keypoints1, img2, keypoints2, matches, img_matches);
    imshow("matches", img_matches);
    waitKey(0);

    return 0;
}

编译时出现此错误:

1>------ Build started: Project: opencvreinstated, Configuration: Release x64 ------
1>matcher_simple.obj : error LNK2001: unresolved external symbol "public: __cdecl cv::SURF::SURF(void)" (??0SURF@cv@@QEAA@XZ)
1>matcher_simple.obj : error LNK2001: unresolved external symbol "public: __cdecl cv::SURF::SURF(double,int,int,bool,bool)" (??0SURF@cv@@QEAA@NHH_N0@Z)
1>C:\Users\motiur\documents\visual studio 2012\Projects\opencvreinstated\x64\Release\opencvreinstated.exe : fatal error LNK1120: 2 unresolved externals
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

我已经在 64 位 Release模式下对此进行了测试，我还成功地运行了其他简单的 opencv 示例，例如流式直播视频。我在那里没有这些问题。帮助表示赞赏。谢谢。

Answer 1

您必须在非自由模块中链接，因为这是实现 Surf 功能的地方。

转到项目属性 -> 链接器 -> 输入，然后将诸如 opencv_nonfree246d.dll 之类的东西添加到附加依赖项字段。

详情请见http://docs.opencv.org/doc/tutorials/introduction/windows_visual_studio_Opencv/windows_visual_studio_Opencv.html#the-local-method