Sören Grimm

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In this paper we describe methods to efficiently visualize multiple intersecting volumetric objects. We introduce the concept of V-Objects. V-Objects represent abstract properties of an object connected to a volumetric data source. We present a method to perform direct volume rendering of a scene comprised of an arbitrary number of possibly intersecting(More)
Curved Planar Reformation (CPR) has proved to be a practical and widely used tool for the visualization of curved tubular structures within the human body. It has been useful in medical procedures involving the examination of blood vessels and the spine. However, it is more difficult to use it for large, tubular, structures such as the trachea and the colon(More)
In this paper we present a novel hybrid CPU-GPU approach for rendering curvilinear grids. Visibility sorting is accomplished by parallel peeling cells off the grid, utilizing an active cell peeling front. In each step, we compute the ray-cell intersection coordinates on the GPU, perform accurate volume integration (CPU), and determine the set of active(More)
In volume rendering, it is very difficult to simultaneously visualize interior and exterior structures while preserving clear shape cues. Highly transparent transfer functions produce cluttered images with many overlapping structures, while clipping techniques completely remove possibly important context information. In this paper, we present a new model(More)
(a) (b) (c) (d) Figure 1: Contrast-enhanced CT angiography data set. (a) Gradient-magnitude opacity-modulation. (b) Direct volume rendering. (c) Direct volume rendering with cutting plane. (d) Context-preserving volume rendering. Abstract In volume rendering it is very difficult to simultaneously visualize interior and exterior structures while preserving(More)
Figure 1: Close-up of the visible male. ABSTRACT Most CPU-based volume raycasting approaches achieve high performance by advanced memory layouts, space subdivision, and excessive pre-computing. Such approaches typically need an enormous amount of memory. They are limited to sizes which do not satisfy the medical data used in daily clinical routine. We(More)
Most volume rendering systems based on CPU volume raycasting still suffer from inefficient CPU utilization and high memory usage. To target these issues we present a new technique for efficient data addressing. Furthermore, we introduce a new processing scheme for volume raycasting which exploits thread-level parallelism—a technology now supported by(More)
Currently X-ray mammography is the most widely used method for early detection of breast cancer. However, the use of Dynamic Contrast Enhanced MRI (DCE-MRI) has gained wider attention, since it considerably improves tumor detection and classification by analyzing the flow of contrast agent within the breast tissue. In this paper we present MammoExplorer, a(More)
We present Volume dots (Vots), a new primitive for volumetric data modelling, processing, and rendering. Vots are a point-based representation of volumetric data. An individual Vot is specified by the coefficients of a Taylor series expansion, i.e. the function value and higher order derivatives at a specific point. A Vot does not only represent a single(More)
Volume rendering techniques are conventionally classified into two categories represented by direct and indirect methods. Indirect methods require to transform the initial volumetric model into an intermediate geometrical model in order to efficiently visualize it. In contrast, direct volume-rendering (DVR) methods can directly process the volumetric data.(More)