{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/real-world-repetition-estimation-by-div-grad","title":"Real-World Repetition Estimation by Div, Grad and Curl","arxiv_id":"1802.09971","date":"2018-02-27","proceeding":"CVPR 2018 6","authors":["Tom F. H. Runia","Cees G. M. Snoek","Arnold W. M. Smeulders"],"abstract":"We consider the problem of estimating repetition in video, such as performing\npush-ups, cutting a melon or playing violin. Existing work shows good results\nunder the assumption of static and stationary periodicity. As realistic video\nis rarely perfectly static and stationary, the often preferred Fourier-based\nmeasurements is inapt. Instead, we adopt the wavelet transform to better handle\nnon-static and non-stationary video dynamics. From the flow field and its\ndifferentials, we derive three fundamental motion types and three motion\ncontinuities of intrinsic periodicity in 3D. On top of this, the 2D perception\nof 3D periodicity considers two extreme viewpoints. What follows are 18\nfundamental cases of recurrent perception in 2D. In practice, to deal with the\nvariety of repetitive appearance, our theory implies measuring time-varying\nflow and its differentials (gradient, divergence and curl) over segmented\nforeground motion. For experiments, we introduce the new QUVA Repetition\ndataset, reflecting reality by including non-static and non-stationary videos.\nOn the task of counting repetitions in video, we obtain favorable results\ncompared to a deep learning alternative.","url_abs":"http://arxiv.org/abs/1802.09971v1","url_pdf":"http://arxiv.org/pdf/1802.09971v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"abstracts"},"code_links":[],"tasks":[],"methods":[],"datasets_introduced":[{"slug":"quva-repetition","name":"QUVA Repetition","full_name":""}],"methods_introduced":[],"results":[],"syntology":{"syntology_url":"https://syntology.ai/paper/1802.09971","atlas_url":"https://app.syntology.ai/?focus=1802.09971","mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}