Oliver Mattausch | Swiss Federal Institute of Technology (ETH) (original) (raw)

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Papers by Oliver Mattausch

2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015

Numerical simulation of ultrasound images can facilitate the training of sonographers. A realisti... more Numerical simulation of ultrasound images can facilitate the training of sonographers. A realistic appearance of simulated ultrasonic speckle is essential for a plausible ultrasound simulation. An efficient and realistic model for ultrasonic speckle is the convolution of the ultrasound point-spread function with a parametrized distribution of point scatterers. Nevertheless, for a given arbitrary tissue, such scatterer distributions that would generate a realistic image are not known a priori, and currently there is no principled method to extract such scatterer patterns for given target tissues to be simulated. In this paper we propose to solve the inverse problem, in which an underlying scatterer map for a given sample ultrasound image is estimated. From such scatterer maps, it is also shown that a parametrization distribution model can be built, using which other instances of the same tissue can be simulated by feeding into a standard speckle generation method. This enables us to synthesize images of different tissue types from actual ultrasound images to be used in simulations with arbitrary view angles and transducer settings. We show in numerical and physical tissue-mimicking phantoms and actual physical tissue that the appearance of the synthesized images closely match the real images.

Computer Graphics Forum, 2015

ACM Transactions on Applied Perception, 2014

Proceedings of the 18th spring conference on Computer graphics - SCCG '03, 2003

Advanced Rendering Techniques, 2012

ABSTRACT Standard online occlusion culling is able to vastly improve the rasterization performanc... more ABSTRACT Standard online occlusion culling is able to vastly improve the rasterization performance of walkthrough applications by identifying large parts of the scene as invisible from the camera and rendering only the visible geometry. However, it is of little use for the acceleration of shadow map generation (i.e., rasterizing the scene from the light view [Williams 78]), so that typically a high percentage of the geometry will be visible when rendering shadow maps. For example, in outdoor scenes typical viewpoints are near the ground and therefore have significant occlusion, while light viewpoints are higher up and see most of the geometry. Our algorithm remedies this situation by quickly detecting and culling the geometry that does not contribute to the shadow in the final image.

ABSTRACT This article presents a method which minimizes the overhead associated with occlusion qu... more ABSTRACT This article presents a method which minimizes the overhead associated with occlusion queries. The method reduces the number of required state changes and should integrate easily with most game engines. The key ideas are batching of the queries and interfacing with the game engine using a dedicated render queue. We also present some additional optimizations which reduce the number of queries issued as well as the number of rendered primitives. The algorithm is based on the well-known Coherent Hierarchical Culling algorithm.