single-marker tracking and (b) adaptive tracking with 2 markers. If marker 1 becomes obscured, the algorithm switches to marker 2 (if visible) to reconstruct the location of marker 1 and provide correct feedback. 3744 Optical Motion Tracking With Two Markers for Robust Prospective Motion Correction Aditya Singh, Benjamin Zahneisen, Brian Keating, Michael Herbst, Maxim Zaitsev, and Thomas Ernst ...

The synergy between in-room imaging and optical tracking, in co-operation with highly accurate robotic patient handling represents a concept for patient-set-up which has been implemented at CNAO (Centro Nazionale di Adroterapia Oncologica). In-room imaging is based on a double oblique X-ray projection system; optical tracking consists of the detection of the position of spherical markers placed...

In this paper, we present two new observation models based on optical flow information to track objects using particle filter algorithms. Although optical flow information enables us to know the displacement of objects present in a scene, it cannot be used directly to displace an object model since flow calculation techniques lack the necessary precision. In view of the fact that probabilistic ...

This paper describes a robust method for the local optical flow estimation and the KLT feature tracking performed on the GPU. Therefore we present an estimator based on the L norm with robust characteristics. In order to increase the robustness at discontinuities we propose a strategy to adapt the used region size. The GPU implementation of our approach achieves real-time (>25fps) performance f...

In this paper, we define an observation model based on optical flow information to track objects using particle filter algorithms. Although the optical flow information enables us to know the displacement of objects present in a scene, it cannot be used directly to displace an object model since flow calculation techniques lack the necessary precision. In view of the fact that probabilistic tra...

Skin color is an important visual cue for computer vision systems involving human users. In this paper we combine skin color and optical flow for detection and tracking of skin regions. We apply these techniques to gesture recognition with encouraging results. We propose a novel skin similarity measure. For grouping detected skin regions we propose a novel skin region grouping mechanism. The pr...

Over the past few years, virtual studios applications have significantly attracted the attention of the entertainment in­ dustry. Optical tracking systems for virtual sets produc­ tion have become particularly popular tending to substitute electro-mechanical ones. In this work, an existing optical tracking system [IJ is revisited, in order to tackle with inher­ ent degenerate cases; namely, red...

As interest in anisotropic particles has increased in various research fields, methods of tracking such particles have become increasingly desirable. Here, we present a new and intuitive method to monitor the Brownian motion of a nanowire, which can construct and visualize multi-dimensional motion of a nanowire confined in an optical trap, using a dual particle tracking system. We measured the ...

ABSTRACT In this paper, model-based and model-free image based visual servoing (VS) approaches are implemented on a microassembly workstation, and their regulation and tracking performances are evaluated. A precise image based VS relies on computation of the image jacobian. In the modelbased visual servoing, the image Jacobian is computed via calibrating the optical system. Precisely calibrated...