本文介绍了如何使用opencv flann :: Index?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我对opencv flann :: Index有一些问题 -



我正在创建索引

  Mat samples = Mat :: zeros(vfv_net_quie.size(),24,CV_32F); 
for(int i = 0; i< vfv_net_quie.size(); i ++)
{
for(int j = 0; j {
samples.at< float>(i,j)=(float)vfv_net_quie [i] .vfv [j]
}
}
cv :: flann :: Index flann_index(
samples,
cv :: flann :: KDTreeIndexParams(4),
cvflann: :FLANN_DIST_EUCLIDEAN
);
flann_index.save(c:\\index.fln);

这是我试图加载它并找到最近的neiborhoods

  cv :: flann :: Index flann_index(Mat(),
cv :: flann :: SavedIndexParams(c:\\index .fln),
cvflann :: FLANN_DIST_EUCLIDEAN
);

cv :: Mat resps(vfv_reg_quie.size(),K,CV_32F);
cv :: Mat nresps(vfv_reg_quie.size(),K,CV_32S);
cv :: Mat dists(vfv_reg_quie.size(),K,CV_32F);

flann_index.knnSearch(sample,nresps,dists,K,cv :: flann :: SearchParams(64));

在miniflann.cpp行中存在违规行

 ((IndexType *)index) - > knnSearch(_query,_indices,_dists,knn,
(const :: cvflann :: SearchParams&)get_params ));

请帮助

解决方案

不应将flann文件加载到 Mat()中,因为它是存储索引的位置。它是在调用构造函数之后销毁的临时对象。这就是为什么当你调用 knnSearch()时,索引不指向任何有用的原因。



/ p>

  cv :: Mat indexMat; 
cv :: flann :: Index flann_index(
indexMat,
cv :: flann :: SavedIndexParams(c:\\index.fln),
cvflann: :FLANN_DIST_EUCLIDEAN
);

导致:

 读取FLANN索引错误:保存的数据大小(100,64)或类型(5)不同于传递的(0,0),0 

这意味着矩阵必须以正确的维度初始化(对我来说似乎很蠢,因为我不一定知道,有多少元素存储在我的索引中)。

  cv :: Mat indexMat(samples.size(),CV_32FC1); 
cv :: flann :: Index flann_index(
indexMat,
cv :: flann :: SavedIndexParams(c:\\index.fln),
cvflann: :FLANN_DIST_EUCLIDEAN
);

I have some problems with opencv flann::Index -

I'm creating index

    Mat samples = Mat::zeros(vfv_net_quie.size(),24,CV_32F);
        for (int i =0; i < vfv_net_quie.size();i++)
        {
           for (int j = 0;j<24;j++)
           {
              samples.at<float>(i,j)=(float)vfv_net_quie[i].vfv[j];
           }
        }
    cv::flann::Index flann_index(
            samples,
            cv::flann::KDTreeIndexParams(4),
            cvflann::FLANN_DIST_EUCLIDEAN
               );
    flann_index.save("c:\\index.fln");

A fter that I'm tryin to load it and find nearest neiborhoods

cv::flann::Index flann_index(Mat(),
    cv::flann::SavedIndexParams("c:\\index.fln"),
    cvflann::FLANN_DIST_EUCLIDEAN
    );

cv::Mat resps(vfv_reg_quie.size(), K, CV_32F);
cv::Mat nresps(vfv_reg_quie.size(), K, CV_32S);
cv::Mat dists(vfv_reg_quie.size(), K, CV_32F);

flann_index.knnSearch(sample,nresps,dists,K,cv::flann::SearchParams(64));

And have access violation in miniflann.cpp in line

((IndexType*)index)->knnSearch(_query, _indices, _dists, knn,
                          (const ::cvflann::SearchParams&)get_params(params));

Please help

解决方案

You should not load the flann-file into a Mat(), as it is the place where the index is stored. It is a temporary object destroyed after the constructor was called. That's why the index isn't pointing anywhere useful when you call knnSearch().

I tried following:

cv::Mat indexMat;
cv::flann::Index flann_index(
    indexMat,
    cv::flann::SavedIndexParams("c:\\index.fln"),
    cvflann::FLANN_DIST_EUCLIDEAN
);

resulting in:

Reading FLANN index error: the saved data size (100, 64) or type (5) is different from the passed one (0, 0), 0

which means, that the matrix has to be initialized with the correct dimensions (seems very stupid to me, as I don't necessarily know, how many elements are stored in my index).

cv::Mat indexMat(samples.size(), CV_32FC1);
cv::flann::Index flann_index(
    indexMat,
    cv::flann::SavedIndexParams("c:\\index.fln"),
    cvflann::FLANN_DIST_EUCLIDEAN
);

does the trick.

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10-15 21:19