Signal-Specialized Parameterization

To reduce memory requirements for texture mapping a model, we build a surface parametrization specialized to its signal (such as color or normal). Intuitively, we want to allocate more texture samples in regions with greater signal detail. Our approach is to minimize signal approximation error --- the difference between the original surface signal and its reconstruction from the sampled texture. Specifically, our signal-stretch parametrization metric is derived from a Taylor expansion of signal error. For fast evaluation, this metric is pre-integrated over the surface as a metric tensor. We minimize this nonlinear metric using a novel coarse-to-fine hierarchical solver, further accelerated with a fine-to-coarse propagation of the integrated metric tensor. Use of metric tensors permits anisotropic squashing of the parametrization along directions of low signal gradient. Texture area can often be reduced by a factor of 4 for a desired signal accuracy compared to non-specialized parametrizations.Engineering and Applied Science

Discontinuity Edge Overdraw

Aliasing is an important problem when rendering triangle meshes. Efficient antialiasing techniques such as mipmapping greatly improve the filtering of textures defined over a mesh. A major component of the remaining aliasing occurs along discontinuity edges such as silhouettes, creases, and material boundaries. Framebuffer supersampling is a simple remedy, but 2x2 supersampling leaves behind significant temporal artifacts, while greater supersampling demands even more fill-rate and memory. We present an alternative that focuses effort on discontinuity edges by overdrawing such edges as antialiased lines. Although the idea is simple, several subtleties arise. Visible silhouette edges must be detected efficiently. Discontinuity edges need consistent orientations. They must be blended as they approach the silhouette to avoid popping. Unfortunately, edge blending results in blurriness. Our technique balances these two competing objectives of temporal smoothness and spatial sharpness. Finally, the best results are obtained when discontinuity edges are sorted by depth. Our approach proves surprisingly effective at reducing temporal artifacts commonly referred to as "crawling jaggies," with little added cost.Engineering and Applied Science

Geometry videos

We present the "Geometry Video," a new data structure to encode animated meshes. Being able to encode animated meshes in a generic source-independent format allows people to share experiences. Changing the viewpoint allows more interaction than the fixed view supported by 2D video. Geometry videos are based on the "Geometry Image" mesh representation introduced by Gu et al. Our novel data structure provides a way to treat an animated mesh as a video sequence (i.e., 3D image) and is well suited for network streaming. This representation also offers the possibility of applying and adapting existing mature video processing and compression techniques (such as MPEG encoding) to animated meshes. This paper describes an algorithm to generate geometry videos from animated meshes.The main insight of this paper, is that Geometry Videos re-sample and re-organize the geometry information, in such a way, that it becomes very compressible. They provide a unified and intuitive method for level-of-detail control, both in terms of mesh resolution (by scaling the two spatial dimensions) and of frame rate (by scaling the temporal dimension). Geometry Videos have a very uniform and regular structure. Their resource and computational requirements can be calculated exactly, hence making them also suitable for applications requiring level of service guarantees.Engineering and Applied Science

Kaposi's sarcoma in a patient with erythroblastopenia and thymoma: Reactivation after topical corticosteroids

We report a 69-year-old female with erythroblastopenia and thymoma who developed lesions of Kaposi's sarcoma (KS) after thymectomy, 2 months after the initiation of therapy with methylprednisolone. Control of mucocutaneous KS lesions was obtained with radiotherapy, interferon alfa-2b and withdrawal of systemic immunosuppressive therapy. Erosive oral lichen planus appeared later, and after therapy with topical corticosteroids a new lesion of KS developed that regressed after withdrawal of topical corticosteroids. The detection of HHV-8 only in lesional skin supports the hypothesis that this virus can trigger the development of KS lesions

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO