https://www.cs.ucla.edu/~dt/papers/mia96/mia96.pdf

Deformable models in medical image analysis: a survey

In recent years, many shape representations and geometric algorithms have been proposed for matching 3D shapes. Usually, each algorithm is tested on a different (small) database of 3D models, and thus no direct comparison is available for competing methods. We describe the Princeton Shape Benchmark (PSB), a publicly available database of polygonal models collected from the World Wide Web and a suite of tools for comparing shape matching and classification algorithms. One feature of the benchmark is that it provides multiple semantic labels for each 3D model. For instance, it includes one classification of the 3D models based on function, another that considers function and form, and others based on how the object was constructed (e.g., man-made versus natural objects). We find that experiments with these classifications can expose different properties of shape-based retrieval algorithms. For example, out of 12 shape descriptors tested, extended Gaussian images by B. Horn (1984) performed best for distinguishing man-made from natural objects, while they performed among the worst for distinguishing specific object types. Based on experiments with several different shape descriptors, we conclude that no single descriptor is best for all classifications, and thus the main contribution of this paper is to provide a framework to determine the conditions under which each descriptor performs best.

/pdf/the-princeton-shape-benchmark-2gmwi9i096.pdf

The Princeton Shape Benchmark

BackgroundLung auscultation and bedside chest radiography are routinely used to assess the respiratory condition of ventilated patients with acute respiratory distress syndrome (ARDS). Clinical experience suggests that the diagnostic accuracy of these procedures is poor.MethodsThis prospective study

Comparative Diagnostic Performances of Auscultation, Chest Radiography, and Lung Ultrasonography in Acute Respiratory Distress Syndrome

Recent developments in techniques for modeling, digitizing and visualizing 3D shapes has led to an explosion in the number of available 3D models on the Internet and in domain-specific databases. This has led to the development of 3D shape retrieval systems that, given a query object, retrieve similar 3D objects. For visualization, 3D shapes are often represented as a surface, in particular polygonal meshes, for example in VRML format. Often these models contain holes, intersecting polygons, are not manifold, and do not enclose a volume unambiguously. On the contrary, 3D volume models, such as solid models produced by CAD systems, or voxels models, enclose a volume properly. This paper surveys the literature on methods for content based 3D retrieval, taking into account the applicability to surface models as well as to volume models. The methods are evaluated with respect to several requirements of content based 3D shape retrieval, such as: (1) shape representation requirements, (2) properties of dissimilarity measures, (3) efficiency, (4) discrimination abilities, (5) ability to perform partial matching, (6) robustness, and (7) necessity of pose normalization. Finally, the advantages and limitations of the several approaches in content based 3D shape retrieval are discussed.

/pdf/a-survey-of-content-based-3d-shape-retrieval-methods-1p1e9hurpn.pdf

A survey of content based 3D shape retrieval methods

The American Thoracic Society/European Respiratory Society jointly created a Task Force on "Outcomes for COPD pharmacological trials: from lung function to biomarkers" to inform the chronic obstructive pulmonary disease research community about the possible use and limitations of current outcomes and markers when evaluating the impact of a pharmacological therapy. Based on their review of the published literature, the following document has been prepared with individual sections that address specific outcomes and markers, and a final section that summarises their recommendations.

/pdf/outcomes-for-copd-pharmacological-trials-from-lung-function-4a4k924y7q.pdf

Outcomes for COPD pharmacological trials: From lung function to biomarkers

This paper introduces a new compression scheme, so- called Multi-Chart Geometry Video (MCGV), for 3D dynamic meshes with constant connectivity and time-varying geometry. The core of the proposed method is a piecewise affine predictor coupled with a Multi-Chart Geometry IMage (MCGIM) representation of the residual errors. The mesh is first partitioned into vertex clusters whose motion can be accurately described by a unique 3D affine transform. The prediction errors are represented as MCGIMs which are compressed by using standardized image encoders such as JPEG and MPEG-4. The performances of our encoder are objectively evaluated on a data set of six animation sequences with various sizes, geometries and topologies, and exhibiting both rigid and elastic motions. The experimental evaluation shows that the proposed MCGV achieves up to 60% lower compression distortions than the geometry video approach, while outperforming (with 30% to 94% lower distortions) the RT, MPEG-4IAFX-IC, D3DMC, PCA and Dynapack techniques.

Multi-Chart Geometry Video: A Compact Representation for 3D Animations

In this study, we assessed the relationship between brain estimated specific gravity (eSG) and clinical symptoms, therapeutic intensity level, and outcome in human traumatic brain injury (TBI). Brain weight, volume, and eSG of the noncontused hemispheric areas were measured from computed tomography

Computed tomography-estimated specific gravity of noncontused brain areas as a marker of severity in human traumatic brain injury.

This paper introduces a new compression scheme for 3D dynamic meshes with constant connectivity and time-varying geometry. The proposed approach, referred to as Temporal-CT encoder (TDCT), combines a piecewise affine prediction scheme with a temporal DCT-based compression of the prediction errors. Experiments show that TDCT achieves up to 70% and 54% lower compression distortions than the GV and MCGV approaches, while outperforming (47% to 95% lower distortions) RT, MPEG-4/AFX-IC, D3DMC and Dynapack techniques.

http://www.wseas.us/e-library/conferences/2006cscc/papers/534-323.pdf

Temporal DCT-based compression of 3D dynamic meshes

Under the framework of the watermarking applications, to accurately model the malicious attacks becomes nowadays a challenging research topic Following a previous study pointing out the inner limitations of the popular Gaussian model, this paper computes for the first time accurate approximations for the zero memory information sources describing some main real life attacks in video watermarking: linear and non-linear filtering, rotations, and StirMark (which may emulate the in-theatre camcorder capture) In order to obtain these models, the authors advance an original and generic statistical approach for pdf estimation combining EM Gaussian mixtures and confidence limits This investigation procedure does not rely on any a priori assumption concerning the video/attack stationarity and handles with mathematical rigour the dependency existing among successive frames in a video sequence

Zero memory information sources approximating to video watermarking attacks

Enriched multimedia applications and services aim at combining images, sounds, videos, and synthetic objects into hybrid and interactive scenes. The core technologies discussed here deal with the representation and integration within such complex scenes of a specific kind of synthetic data, namely virtual character animation. This paper analyzes how an integrated and standardized framework is currently emerging in order to ensure application interoperability, universal content access, and user interactivity. We first compare how virtual character animation has been addressed within virtual reality modeling language (VRML) and MPEG-4 synthetic and natural hybrid coding standardization processes. A comparative synthesis between the objectives and the capabilities of each framework is exposed, specifically MPEG-4 Face and Body Animation (FBA) versus H-Anim (Humanoid Animation Working Group, WEB3D Consortium, h-anim.org.) 1.1, and MPEG-4 Bone-Based Animation (BBA) versus H-Anim 2001. The Animation Framework eXtension (AFX) specifications that are a part of MPEG-4 Systems Part 16 include the BBA framework. The BBA animation concepts, based on generic skeleton representation and curve-based deformations, are introduced. The definition of the related nodes and how they successfully address the BBA concepts are as well discussed. Some comments with respect to the rotation representation, the interpolation methods, the animation mask, and value parameters of the animation stream are made. This set of specifications provides an efficient framework, which is appropriate to real-time and animation realistic applications within networked environments.

Francoise Preteux

Papers

Multi-Chart Geometry Video: A Compact Representation for 3D Animations

Computed tomography-estimated specific gravity of noncontused brain areas as a marker of severity in human traumatic brain injury.

Temporal DCT-based compression of 3D dynamic meshes

Zero memory information sources approximating to video watermarking attacks

Virtual character within MPEG-4 animation framework eXtension