1,095 research outputs found
A PDE Approach to Data-driven Sub-Riemannian Geodesics in SE(2)
We present a new flexible wavefront propagation algorithm for the boundary
value problem for sub-Riemannian (SR) geodesics in the roto-translation group
with a metric tensor depending on a smooth
external cost , , computed from
image data. The method consists of a first step where a SR-distance map is
computed as a viscosity solution of a Hamilton-Jacobi-Bellman (HJB) system
derived via Pontryagin's Maximum Principle (PMP). Subsequent backward
integration, again relying on PMP, gives the SR-geodesics. For
we show that our method produces the global minimizers. Comparison with exact
solutions shows a remarkable accuracy of the SR-spheres and the SR-geodesics.
We present numerical computations of Maxwell points and cusp points, which we
again verify for the uniform cost case . Regarding image
analysis applications, tracking of elongated structures in retinal and
synthetic images show that our line tracking generically deals with crossings.
We show the benefits of including the sub-Riemannian geometry.Comment: Extended version of SSVM 2015 conference article "Data-driven
Sub-Riemannian Geodesics in SE(2)
Emerging coordination mechanisms for multi-party IPR holders: linking research with standardization
The standards setting process relies to an increasing degree on successfully integrating up-to-date research and development results (R&D). The successful interaction between research and standards can provide important social benefits. But, to do so, a number of challenges need to be faced. One key and persistent challenge is to provide the conditions in which the cross-purposes of formal standards-setting bodies and intellectual property rights can equitably be accommodated. This means balancing the collective gains to be reaped from the elaboration of a common standard against the individual gains to be allocated to relevant individual rights-holders. This discussion paper focuses on approaches to the reemerging tension between intellectual-property-rights and standards. It points to the importance that successful approaches can have to improve the interaction the between research and standardization activities. It then goes on to consider the (re)emergence of two approaches that are indicative of the changing relationship between intellectual property rights and standards-setting bodies
Vesselness via multiple scale orientation scores
The multi-scale Frangi vesselness filter is an established tool in (retinal) vascular imaging. However, it cannot cope with crossings or bifurcations, since it only looks for elongated structures. Therefore, we disentangle crossing structures in the image via (multiple scale) invertible orientation scores. The described vesselness filter via scale-orientation scores performs considerably better at enhancing vessels throughout crossings and bifurcations than the Frangi version. Both methods are evaluated on a public dataset. Performance is measured by comparing ground truth data to the segmentation results obtained by basic thresholding and morphological component analysis of the filtered images
Fourier Transform on the Homogeneous Space of 3D Positions and Orientations for Exact Solutions to Linear PDEs
Determining factors of the effectiveness of IP-based spin-offs:Comparing the Netherlands and the US
Roto-translation equivariant convolutional networks: Application to histopathology image analysis
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