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

In the absence of any theoretical or experimental support, the video watermarking attacks are by default assumed to be Gaussian distributed. By combining four types of statistical tests, the present paper carries out an in-depth study on this hypothesis for eight types of attacks: filtering (median, Gaussian, FMLR, sharpening), rotations, JPEG compression, row&column removal, and StirMark. These attacks are investigated in the hierarchy of the DCT and DWT coefficients. The results in this paper show that the Gaussian assumption can be rejected for most of the attacks. Finally, the non-Gaussian behaviour impact on several applications connected to video watermarking capacity is discussed.

Gaussian Hypothesis for Video Watermarking Attacks: Drawbacks and Limitations

This paper addresses the issue of oblivious robust watermarking, within the framework of colour still image database protection. We present an original method which complies with all the requirements nowadays imposed to watermarking applications: robustness (e.g. low-pass filtering, print & scan, StirMark), transparency (both quality and fidelity), low probability of false alarm, obliviousness and multiple bit recovering. The mark is generated from a 64 bit message (be it a logo, a serial number, etc.) by means of a Spread Spectrum technique and is embedded into DWT (Discrete Wavelet Transform) domain, into certain low frequency coefficients, selected according to the hierarchy of their absolute values. The best results were provided by the (9,7) bi-orthogonal transform. The experiments were carried out on 1200 image sequences, each of them of 32 images. Note that these sequences represented several types of images: natural, synthetic, medical, etc. and each time we obtained the same good results. These results are compared with those we already obtained for the DCT domain, the differences being pointed out and discussed.

Wavelet versus DCT-based spread spectrum watermarking of image databases

The explosion of VoD and HDTV services opened a new direction in watermarking applications: compressed domain watermarking, promising at least tenfold speed increase. While sound technical approaches to this emerging field are already available in the literature, at our best knowledge the present paper is the first related theoretical study. It considers the ISO/IEC 14496-10:2005 standard (also known as MPEG-4 AVC) and objectively describes with information theory concepts (noisy channel, noise matrices) the effects of the real-life watermarking attacks (like rotations, linear and non-linear filtering, StirMark). All the results are obtained on a heterogeneous corpus of 7 video sequences summing up to about 3 hours.

The watermarking attacks in the MPEG-4 AVC domain

Nowadays, nobody doubts about the huge economical benefits the watermarking solutions will one day bring. The paper
is devoted to the theoretical evaluation of the watermarking capacity, i.e. devoted to find out with mathematical rigour
the maximum amount of information which can be inserted into the DWT of natural video, for prescribed constraints of
transparency and robustness. The starting point is the accurate statistical model for the watermarking attacks the authors
already reported. In this paper, in addition to the classical Shannon solutions, the capacity is evaluated by two
approaches: (1) a method developed in order to increase speed and precision for watermarking evaluations and (2) the
general Blahut-Arimoto algorithm, adapted by Justin Dauwels for the discrete case. The experiments are run on a video
corpus of 10 video sequences of about 25 minutes each.

Theoretical limits in DWT video watermarking

This paper introduces a new interactive mobile TV application related to parliament session. This application aims to
provide additional information to mobile TV users by inserting automatically and in real-time interactive contents
(complementary information, subject of the current session...) into original TV program, using MPEG-4 streaming video
and extra real time information (news, events, databases... from RSS streams, Internet links...). Here, we propose an
architecture based on plug-in multimedia analyzers to generate the contextual description of the media and on an
interactive scene generator to dynamically create related interactive scenes. Description is implemented according to the
MPEG-7 standard.

Francoise Preteux

Papers

Gaussian Hypothesis for Video Watermarking Attacks: Drawbacks and Limitations

Wavelet versus DCT-based spread spectrum watermarking of image databases

The watermarking attacks in the MPEG-4 AVC domain

Theoretical limits in DWT video watermarking

Interactive TV on parliament session