{"id":30915458,"url":"https://github.com/mstorath/circlemedianfilter","last_synced_at":"2025-09-09T23:27:51.976Z","repository":{"id":178174252,"uuid":"87291170","full_name":"mstorath/CircleMedianFilter","owner":"mstorath","description":"Fast median filter for circle-valued data, for example signals or images describing phase or orientation","archived":false,"fork":false,"pushed_at":"2025-06-27T08:03:54.000Z","size":2567,"stargazers_count":16,"open_issues_count":0,"forks_count":6,"subscribers_count":2,"default_branch":"master","last_synced_at":"2025-09-08T04:23:51.036Z","etag":null,"topics":["circle","cpp","denoising","manifold","matlab","median-filtering","orientation","orientation-data","phase","python3","unit-circle"],"latest_commit_sha":null,"homepage":"https://mstorath.github.io/CircleMedianFilter/","language":"C++","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/mstorath.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2017-04-05T09:25:07.000Z","updated_at":"2025-06-27T07:58:49.000Z","dependencies_parsed_at":null,"dependency_job_id":"ee7846dd-82d5-47aa-85c4-04ca96fe50ec","html_url":"https://github.com/mstorath/CircleMedianFilter","commit_stats":null,"previous_names":["mstorath/circlemedianfilter"],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/mstorath/CircleMedianFilter","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mstorath%2FCircleMedianFilter","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mstorath%2FCircleMedianFilter/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mstorath%2FCircleMedianFilter/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mstorath%2FCircleMedianFilter/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/mstorath","download_url":"https://codeload.github.com/mstorath/CircleMedianFilter/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mstorath%2FCircleMedianFilter/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":274382340,"owners_count":25274819,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-09-09T02:00:10.223Z","response_time":80,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["circle","cpp","denoising","manifold","matlab","median-filtering","orientation","orientation-data","phase","python3","unit-circle"],"created_at":"2025-09-09T23:27:47.281Z","updated_at":"2025-09-09T23:27:51.953Z","avatar_url":"https://github.com/mstorath.png","language":"C++","readme":"# Circle median filter toolbox (CMF)\n \nThis toolbox contains a fast algorithm for median filtering of signals and images with values on the unit circle, for example phase or orientation data.\nThe (arc distance) median filter for an image y with values on the unit circle is given by \n\n\u003cimg src=\"docs/eqArcDistanceMedian.png\" width=\"40%\"\u003e\n\nwhere d denotes the arc distance length of two angles, and r, t are the horizontal and vertical \"radii\" of the filter mask.\n\nThe code is a reference implementation (in C++ with Matlab wrappers) of the algorithms described in the paper:\n\nMartin Storath, Andreas Weinmann.\n[Fast median filtering for phase or orientation data.](https://doi.org/10.1109/TPAMI.2017.2692779)\nIEEE Transactions on Pattern Analysis and Machine Intelligence, \t40(3):639-652, 2018  ([preprint](https://hci.iwr.uni-heidelberg.de/sites/default/files/profiles/mstorath/files/storath2017fast.pdf))\n\nSee also [![View Circle Median Filter on File Exchange](https://www.mathworks.com/matlabcentral/images/matlab-file-exchange.svg)](https://de.mathworks.com/matlabcentral/fileexchange/62509-circle-median-filter)\n\n## Updates\n- 2025/02/18: Added Python bindings for the core C++ filtering code. See installation notes below.\n\n\n\n### Example \n\n\n![alt tag](https://hci.iwr.uni-heidelberg.de/sites/default/files/publications/teaserimages/1908951751/mediancircularrevision_teaser_small.png)\n\n*Left:* A circle-valued image, i.e. every pixel takes its value on the unit circle (or in angular representation a value in (-pi, pi]). The values are visualized as hue component in the HSV color space.\n*Right:* Effect of the circle-median filter using a filter mask of size 7 × 7. \n\n### Runtime comparison\n\nThe time complexity w.r.t. the size of the filter mask is\n- linear for non-quantized data\n- constant for quantized data\n\n\u003cimg src=\"docs/runtime.png\" width=\"80%\"\u003e\n\n### Applications\n\n- Smoothing of phase data, e.g. interferometric SAR images\n   ![alt tag](docs/InSAR.png)\n- Smoothing of orientation data, e.g. wind directions\n\n   \u003cimg src=\"docs/windDirections.png\" width=\"60%\"\u003e\n   \n- Smoothing of vector fields in polar coordinates, e.g. optical flow images\n\n### Contents\n- demos:     some demos, self explanatory (implemented in Matlab)\n- auxiliary: some useful helper functions (implemented in Matlab)\n- filters:   the fast algorithms for median filtering of circle valued data \n(implemented in C++ with Matlab wrappers)\n\n## Installation and usage \n\n## Python\n- Installation via ```pip install pycirclemedianfilter```.\n- **Important:** The underlying implementation expects *column-major order* arrays. So convert data by ```data = np.asfortranarray(data)``` if necessary before calling the filter function. See the demos_python folder for examples.\n\n## Matlab\n- From Matlab: Run CMF_install.m in the Matlab console and follow the demos \n- From C++: Compile CMF_library.cpp. The relevant functions are medfiltCirc2D and medfiltCirc2DQuant. Their usage is described as comment in the CMF_library.cpp file.\n\n\n\n## References\n### How to cite\n- M. Storath, A. Weinmann. [Fast median filtering for phase or orientation data.](https://doi.org/10.1109/TPAMI.2017.2692779) IEEE Transactions on Pattern Analysis and Machine Intelligence, 40(3):639-652, 2018\n### Selected user applications\n- S. Quan et al. Derivation of the Orientation Parameters in Built-Up Areas: With Application to Model-Based Decomposition. IEEE Transactions on Geoscience and Remote Sensing, 2018\n- H. Salmane et al. A method for the automated detection of solar radio bursts in dynamic spectra. J. Space Weather Space Clim. 2018\n- S. Quan et al., Derivation of the Orientation Parameters in Built-Up Areas: With Application to Model-Based Decomposition. IEEE Transactions on Geoscience and Remote Sensing. 2018\n- B. Guo, J. Wen, Y. Han. Deep Material Recognition in Light-Fields via Disentanglement of Spatial and Angular Information. ECCV 2020\n","funding_links":[],"categories":[],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmstorath%2Fcirclemedianfilter","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fmstorath%2Fcirclemedianfilter","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmstorath%2Fcirclemedianfilter/lists"}