# \#xfeatures2d **URL:** https://forum.opencv.org/tag/xfeatures2d/241.md [Latest](https://forum.opencv.org/latest.md) · [Categories](https://forum.opencv.org/categories.md) · [Tags](https://forum.opencv.org/tags.md) --- ## [Opencv and python: matchLOGOS not working](https://forum.opencv.org/t/opencv-and-python-matchlogos-not-working/15471)
**Author:** [@elephant](https://forum.opencv.org/u/elephant)\ **Replies:** 3\ **Last updated:** [November 10, 2023, 3:11pm UTC](https://forum.opencv.org/t/opencv-and-python-matchlogos-not-working/15471 "2023-11-10T15:11:16Z")
I am trying to use matchLOGOS from opencv 4.7.0 and Python 3. But it’s not going well. The documentation says it can be called like this in Python: cv.xfeatures2d.matchLOGOS( keypoints1, keypoints2, nn1, nn2, matches1t… --- ## [OpenCV build from source error](https://forum.opencv.org/t/opencv-build-from-source-error/14616)
**Author:** [@mfatih7](https://forum.opencv.org/u/mfatih7)\ **Replies:** 8\ **Last updated:** [September 25, 2023, 11:26am UTC](https://forum.opencv.org/t/opencv-build-from-source-error/14616 "2023-09-25T11:26:57Z")
Hello I am trying to build OpenCV 4.7 and 4.8 from source code using CMAKE GUI. If I build without setting OPENCV\_EXTRA\_MODULES\_PATH the CMAKE build and generate succeeds and in Visual Studio I can build and install wi… --- ## [Incompatible changes in OpenCV 3.4 / feature detectors?](https://forum.opencv.org/t/incompatible-changes-in-opencv-3-4-feature-detectors/6625)
**Author:** [@Satz\_Klauer](https://forum.opencv.org/u/Satz_Klauer)\ **Replies:** 3\ **Last updated:** [December 9, 2021, 5:01pm UTC](https://forum.opencv.org/t/incompatible-changes-in-opencv-3-4-feature-detectors/6625 "2021-12-09T17:01:48Z")
I’m currently updating my code to work with OpenCV 3.4 and found some incompatibilities. So opencv2/features2d/features2d.hpp still contains cv::SiftFeatureDetector cv::SurfFeatureDetector cv::OrbFeatureDetector are n… --- ## [Is the implementation code of the function (cv::FeatureDetector::detect) open source code?](https://forum.opencv.org/t/is-the-implementation-code-of-the-function-cv-detect-open-source-code/6526)
**Author:** [@xf\_Li](https://forum.opencv.org/u/xf_Li)\ **Replies:** 4\ **Last updated:** [December 4, 2021, 2:18am UTC](https://forum.opencv.org/t/is-the-implementation-code-of-the-function-cv-detect-open-source-code/6526 "2021-12-04T02:18:29Z")
Hello, everyone! Do before CUDA, I’m new in opencv, due to the environment without cudafeatures2d. hpp, so I want to find the source code of CV: : FeatureDetector: : detect(InputArray image, CV\_OU… --- ## [Conflict between OpenCV 4 and cv\_bridge](https://forum.opencv.org/t/conflict-between-opencv-4-and-cv-bridge/6438)
**Author:** [@Elektron97](https://forum.opencv.org/u/Elektron97)\ **Replies:** 1\ **Last updated:** [November 26, 2021, 5:34pm UTC](https://forum.opencv.org/t/conflict-between-opencv-4-and-cv-bridge/6438 "2021-11-26T17:34:43Z")
Hi everyone. I’m starting a project with OpenCV with ROS and i need to use xfeatures2d that is in opencv\_contrib. I follow this instructions and modify my CMake File in this way: cmake\_minimum\_required(VERSION 3.0.2) pr… --- ## [What is the difference between "cv.xfeatures2d.SIFT\_create()" and "cv.SIFT\_create()"](https://forum.opencv.org/t/what-is-the-difference-between-cv-xfeatures2d-sift-create-and-cv-sift-create/5125)
**Author:** [@songyuc](https://forum.opencv.org/u/songyuc)\ **Replies:** 2\ **Last updated:** [September 11, 2021, 7:06am UTC](https://forum.opencv.org/t/what-is-the-difference-between-cv-xfeatures2d-sift-create-and-cv-sift-create/5125 "2021-09-11T07:06:38Z")
Hi, guys, I see that there are two ways of creating a SIFT detector, which are # 1 cv.xfeatures2d.SIFT\_create() # 2 cv.SIFT\_create() so, what is the difference between them? Your answer and guide will be appreciated… --- ## [FlannBasedMatcher parameters explanations ? for camera tampering](https://forum.opencv.org/t/flannbasedmatcher-parameters-explanations-for-camera-tampering/2915)
**Author:** [@PommePomme](https://forum.opencv.org/u/PommePomme)\ **Replies:** 12\ **Last updated:** [April 23, 2021, 6:45am UTC](https://forum.opencv.org/t/flannbasedmatcher-parameters-explanations-for-camera-tampering/2915 "2021-04-23T06:45:05Z")
Hi there, I attempt to compare two images with SURF and FLANN. The first image is basically the first frame captured of a camera when you run the app. The other image change at every frame since it is a video stream. So… --- ## [Custom classifier for gender prediction with masks](https://forum.opencv.org/t/custom-classifier-for-gender-prediction-with-masks/2304)
**Author:** [@Apaul](https://forum.opencv.org/u/Apaul)\ **Replies:** 4\ **Last updated:** [March 23, 2021, 1:28pm UTC](https://forum.opencv.org/t/custom-classifier-for-gender-prediction-with-masks/2304 "2021-03-23T13:28:42Z")
Hello, I have a few questions on how to train a custom openCV classifier. I hope the right people can answer this. I am thinking of training one classifier with masked male images as positive images and masked female… --- ## [How to add or modify SIFT 's funtion](https://forum.opencv.org/t/how-to-add-or-modify-sift-s-funtion/1106)
**Author:** [@lsding140](https://forum.opencv.org/u/lsding140)\ **Replies:** 13\ **Last updated:** [January 27, 2021, 1:18pm UTC](https://forum.opencv.org/t/how-to-add-or-modify-sift-s-funtion/1106 "2021-01-27T13:18:21Z")
In opencv 3.4.3 ,using SIFT I want provide gpyr and dogpyr to produce keypoints and descriptors ,I try to add a function or modify dectectAndCompute()(added gpyr and dogpyr) in files include sift.cpp,features2d.hpp,xfe…