Convolution filtering of continuous signed distance fields for polygonal meshes

Signed distance fields obtained from polygonal meshes are commonly used in various applications. However, they can have C1 discontinuities causing creases to appear when applying operations such as blending or metamorphosis. The focus of this work is to efficiently evaluate the signed distance function and to apply a smoothing filter to it while preserving the shape of the initial mesh. The resulting function is smooth almost everywhere, while preserving the exact shape of the polygonal mesh. Due to its low complexity, the proposed filtering technique remains fast compared to its main alternatives providing C1-continuous distance field approximation. Several applications are presented such as blending, metamorphosis and heterogeneous modelling with polygonal meshes

Graphics

and approved b

Analytics-modulated coding of surveillance video

A method and apparatus for encoding surveillance video where one or more regions of interest are identified and the encoding parameter values associated with those regions are specified in accordance with intermediate outputs of a video analytics process. Such an analytics-modulated video compression approach allows the coding process to adapt dynamically based on the content of the surveillance images. In this manner, the fidelity of the region of interest is increased relative to that of a background region such that the coding efficiency is improved, including instances when no target objects appear in the scene. Better compression results can be achieved by assigning different coding priority levels to different types of detected objects

Analytics-Modulated Coding of Surveillance Video

Video surveillance systems increasingly use H.264 coding to achieve 24 x 7 recording and streaming. However, with the proliferation of security cameras, and the need to store several months of video, bandwidth and storage costs can be significant. We propose a new compression technique to significantly improve the coding efficiency of H.264 for surveillance video. Video content is analyzed and video semantics are extracted using video analytics algorithms such as segmentation, classification and tracking. In contrast to existing approaches, our Analytics-Modulated Compression (AMC) scheme does not require coding of object shape information and produces bit-streams that are standards-compliant and not limited to specific H.264 profiles. Extensive experiments were conducted involving real surveillance scenes. Results show that our technique achieves compression gains of 67% over JM. We also introduced AMC Rate Control (AMC RC) which allocates bits in response to scene dynamics. AMC RC is shown to significantly reduce artifacts in constant-bitrate video at low bitrates

Unwinding the Colon

Abstract. Three dimensional volume datasets are now commonly produced in the medical sciences. These datasets are generated by observational equipment such as CT, MRI, and ultrasound. There is a significant amount of research in techniques to render these datasets quickly and more realistically. However, there is little or no work on intuitive methods to manipulate volume datasets and volume models. For example, one may want to view a colon stretched out or unraveled. While techniques exist to transform polygonal models, similar techniques are not available for volumetric data. In this work, we describe our methodology to “reshape volumes ” and remap existing volumetric datasets using volumetric skeletons. We demonstrate our results by unraveling a 3D colon dataset and discuss the many potential uses of this new visualization methodology. 1

Shape Based Culling for Volume Graphics

This paper describes a technique to improve the rendering time of volumetric datasets using a volumetric skeleton