mirror of
https://github.com/opencv/opencv.git
synced 2026-09-29 04:09:43 +03:00
Anand Mahesh
4acd2ed6cc
BFMatcher::match() with crossCheck=true previously skipped the OCL dispatch in knnMatchImpl entirely, falling back to CPU even when UMat inputs and an OpenCL device were available. This adds ocl_matchWithCrossCheck() for CV_32FC1 descriptors (e.g. SIFT, SURF): both the forward and reverse nearest-neighbour passes run on the GPU via the existing ocl_matchSingle() kernel, then the cross-check filter runs on the CPU. Only two small index arrays (1×N ints) are downloaded — the O(N²×D) distance work stays on the device. The OCL dispatch in knnMatchImpl is also refactored to unify the Mat/UMat train collection selection before branching on crossCheck. On a NVIDIA RTX 3060 with SIFT descriptors the OCL path is 6–9× faster than CPU at 2k–10k features per image. Binary descriptors (ORB, BRIEF — CV_8U) are unaffected; the existing type guard in ocl_matchSingle keeps them on the CPU path as before. Also adds a correctness test (Features2d_BFMatcher_CrossCheck) and an OCL perf test (BruteForceMatcherFixture/MatchCrossCheck).
OpenCV: Open Source Computer Vision Library
Resources
- Homepage: https://opencv.org
- Courses: https://opencv.org/courses
- Docs: https://docs.opencv.org/4.x/
- Q&A forum: https://forum.opencv.org
- previous forum (read only): http://answers.opencv.org
- Issue tracking: https://github.com/opencv/opencv/issues
- Additional OpenCV functionality: https://github.com/opencv/opencv_contrib
- Donate to OpenCV: https://opencv.org/support/
Contributing
Please read the contribution guidelines before starting work on a pull request.
Summary of the guidelines:
- One pull request per issue;
- Choose the right base branch;
- Include tests and documentation;
- Clean up "oops" commits before submitting;
- Follow the coding style guide.
Additional Resources
- Submit your OpenCV-based project for inclusion in Community Friday on opencv.org
- Subscribe to the OpenCV YouTube Channel featuring OpenCV Live, an hour-long streaming show
- Follow OpenCV on LinkedIn for daily posts showing the state-of-the-art in computer vision & AI
- Apply to be an OpenCV Volunteer to help organize events and online campaigns as well as amplify them
- Follow OpenCV on Mastodon in the Fediverse
- Follow OpenCV on Twitter
- OpenCV.ai: Computer Vision and AI development services from the OpenCV team.