删除OpenCV(关键点和描述符）中的匹配项

Delete matches in OpenCV (Keypoints and descriptors)

本文关键字：OpenCV 关键点 描述 删除      更新时间：2023-10-16

我想对照两个火车图像检查一个场景图像。为此，我检测两个训练图像的特征并计算描述符。在检测、计算和匹配场景图像之前，我将删除train1和train2的所有匹配。因为这些匹配将不利于场景图像与train1和train2的匹配。

所以，我将train1和train2进行匹配，并得到与trainIdx和queryIdx匹配的向量。但是，我如何删除train1和train2的关键点向量和描述符矩阵中的这些匹配？

谨致问候，dwi

我会这样做：

std::vector<cv::KeyPoint> keypoints[2];
cv::Mat descriptor[2];
std::vector< cv::DMatch > matches;
/* 
      Write code to generate the keypoints, descriptors and matches here...
      keypoint[0] -> Train Image 1 keypoints
      keypoint[1] -> Train Image 2 keypoints
      descriptor[0] -> Train Image 1 descriptors
      descriptor[1] -> Train Image 2 descriptors
      matches -> matched between train image 1 and 2
*/
// Logic to keep unmatched keypoints and corresponding descriptors
for (int idx = 0; idx < 2; idx++) {
    std::vector<bool> isMatched(keypoints[idx].size(), false);
    // Mark all matched keypoint as true
    for (int i = 0; i < matches.size(); i++) {
        if (idx == 0) {
            isMatched[matches[i].queryIdx] = true;
        }
        else {
            isMatched[matches[i].trainIdx] = true;
        }
    }
    std::vector<cv::KeyPoint>::const_iterator itr = keypoints[idx].begin();
    // New descriptor length will be old descriptor length minus matched keypoints size
    int descriptor_length = keypoints[idx].size() - matches.size();
    // Create temporary descriptor of new descriptor length
    cv::Mat tempDescriptor(descriptor_length, descriptor[idx].cols, descriptor[idx].depth());
    int count = 0;
    for (int i = 0; i < isMatched.size(); i++) {
        // Remove matched keypoints
        if (isMatched[i] == true) {
            itr = keypoints[idx].erase(itr);
        }
        else {
            descriptor[idx].row(i).copyTo(tempDescriptor.row(count));
            itr++;
            count++;
        }
    }
    descriptor[idx].release();
    descriptor[idx] = tempDescriptor.clone();
}

我希望这会有所帮助。

好吧，就像Micka建议的那样，我迭代所有关键点和描述符，并将除匹配项外的所有关键点或描述符添加到一个新的向量/矩阵中。不可能将它们标记为不必要的。

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