New publication: Some video abstraction techniques for displaying body movement in analysis and performance

leonardo-2013Today the MIT Press journal Leonardo has published my paper entitled “Some video abstraction techniques for displaying body movement in analysis and performance”. The paper is a summary of my work on different types of visualisation techniques of music-related body motion. Most of these techniques were developed during my PhD, but have been refined over the course of my post-doc fellowship.

The paper is available from the Leonardo web page (or MUSE), and will also be posted in the digital archive at UiO after the 6 month embargo period.

Citation
A. R. Jensenius. Some video abstraction techniques for displaying body movement in analysis and performance. Leonardo, 46(1):53–60, 2013.

Abstract
This paper presents an overview of techniques for creating visual displays of human body movement based on video recordings. First a review of early movement and video visualization techniques is given. Then follows an overview of techniques that the author has developed and used in the study of music-related body movements: motion history images, motion average images, motion history keyframe images and motiongrams. Finally, examples are given of how such visualization techniques have been used in empirical music research, in medical research and for creative applications.

Citation

@article{Jensenius:2013,
   Author = {Jensenius, Alexander Refsum},
   Journal = {Leonardo},
   Number = {1},
   Pages = {53--60},
   Title = {Some video abstraction techniques for displaying body movement in analysis and performance},
   Volume = {46},
   Year = {2013}}

Paper #2 at SMC 2012: Noise level in IR mocap systems

Yesterday I presented a paper on motiongrams at the Sound and Music Computing conference in Copenhagen. Today I will present the paper A study of the noise-level in two infrared marker-based motion capture systems. This is a quite nerdy, in-depth study of the noise-level of two of our motion capture systems.

Abstract

With musical applications in mind, this paper reports on the level of noise observed in two commercial infrared marker-based motion capture systems: one high-end (Qualisys) and one affordable (OptiTrack). We have tested how various features (calibration volume, marker size, sampling frequency, etc.) influence the noise level of markers lying still, and fixed to subjects standing still. The conclusion is that the motion observed in humans standing still is usually considerably higher than the noise level of the systems. Dependent on the system and its calibration, however, the signal-to-noise-ratio may in some cases be problematic.

Downloads

  • Full paper [PDF]
  • Poster [PDF]


Reference

Jensenius, A. R., Nymoen, K., Skogstad, S. A., and Voldsund, A. (2012). A study of the noise-level in two infrared marker-based motion capture systems. In Proceedings of the 9th Sound and Music Computing Conference, pages 258–263, Copenhagen.

BibTeX

@inproceedings{Jensenius:2012i,
   Address = {Copenhagen},
   Author = {Jensenius, Alexander Refsum and Nymoen, Kristian and Skogstad, St{\aa}le A. and Voldsund, Arve},
   Booktitle = {Proceedings of the 9th Sound and Music Computing Conference},
   Pages = {258--263},
   Title = {A Study of the Noise-Level in Two Infrared Marker-Based Motion Capture Systems},
   Year = {2012}}

Paper #1 at SMC 2012: Evaluation of motiongrams

Today I presented the paper Evaluating how different video features influence the visual quality of resultant motiongrams at the Sound and Music Computing conference in Copenhagen.

Abstract

Motiongrams are visual representations of human motion, generated from regular video recordings. This paper evaluates how different video features may influence the generated motiongram: inversion, colour, filtering, background, lighting, clothing, video size and compression. It is argued that the proposed motiongram implementation is capable of visualising the main motion features even with quite drastic changes in all of the above mentioned variables.

Downloads

  • Full paper [PDF]
  • Poster [PDF]


Reference

Jensenius, A. R. (2012). Evaluating how different video features influence the visual quality of resultant motiongrams. In Proceedings of the 9th Sound and Music Computing Conference, pages 467–472, Copenhagen.

BibTeX

@inproceedings{Jensenius:2012h,
   Address = {Copenhagen},
   Author = {Jensenius, Alexander Refsum},
   Booktitle = {Proceedings of the 9th Sound and Music Computing Conference},
   Pages = {467--472},
   Title = {Evaluating How Different Video Features Influence the Visual Quality of Resultant Motiongrams},
   Year = {2012}}

Building low-cost music controllers

New publication on our Cheapstick music controller:

Cheapstick

 

Reference:
A. R. Jensenius, R. Koehly, and M. M. Wanderley. Building low-cost music controllers. In R. Kronland-Martinet, T. Voinier, and S. Ystad, editors, CMMR 2005, LNCS 3902, pages 123–129. Berlin Heidelberg: Springer-Verlag, 2006. (PDF from Springer)

 

Abstract:
This paper presents our work on building low-cost music controllers intended for educational and creative use. The main idea was to build an electronic music controller, including sensors and a sensor interface, on a “10 euro” budget. We have experimented with turning commercially available USB game controllers into generic sensor interfaces, and making sensors from cheap conductive materials such as latex, ink, porous materials, and video tape. Our prototype controller, the CheapStick, is comparable to interfaces built with commercially available sensors and interfaces, but at a fraction of the price.

 

BibTeX:

@incollection{Jensenius:2006a,
	Author = {Jensenius, Alexander Refsum and Koehly, Rodolphe and Wanderley, Marcelo M.},
	Booktitle = {CMMR 2005, LNCS 3902},
	Editor = {Kronland-Martinet, R. and Voinier, T. and Ystad, S.},
	Pages = {123--129},
	Publisher = {Berlin Heidelberg: Springer-Verlag},
	Title = {Building Low-Cost Music Controllers},
	Year = {2006}}