Study of Subjective and Objective Quality Evaluation of 3D Point Cloud Data by the JPEG Committee

The SC29/WG1 (JPEG) Committee within ISO/IEC is currently working on developing standards for the storage, compression and transmission of 3D point cloud information. To support the creation of these standards, the committee has created a database of 3D point clouds representing various quality levels and use-cases and examined a range of 2D and 3D objective quality measures. The examined quality measures are correlated with subjective judgments for a number of compression levels. In this paper we describe the database created, tests performed and key observations on the problems of 3D point cloud quality assessment

Evaluation of Blur and Gaussian Noise Degradation in Images Using Statistical Model of Natural Scene and Perceptual Image Quality Measure

In this paper we present new method for classification of image degradation type based on Riesz transform coefficients and Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE) that employs spatial coefficients. In our method we use additional statistical parameters that gives us statistically better results for blur and all tested degradations together in comparison with previous method. A new method to determine level of blur and Gaussian noise degradation in images using statistical model of natural scene is presented. We defined parameters for evaluation of level of Gaussian noise and blur degradation in images. In real world applications reference image is usually not available therefore proposed method enables classification of image degradation by type and estimation of Gaussian noise and blur levels for any degraded image

Warsaw Breakage Syndrome associated DDX11 helicase resolves G-quadruplex structures to support sister chromatid cohesion

Warsaw Breakage Syndrome (WABS) is a rare disorder related to cohesinopathies and Fanconi anemia, caused by bi-allelic mutations in DDX11. Here, we report multiple compound heterozygous WABS cases, each displaying destabilized DDX11 protein and residual DDX11 function at the cellular level. Patient-derived cell lines exhibit sensitivity to topoisomerase and PARP inhibitors, defective sister chromatid cohesion and reduced DNA replication fork speed. Deleting DDX11 in RPE1-TERT cells inhibits proliferation and survival in a TP53-dependent manner and causes chromosome breaks and cohesion defects, independent of the expressed pseudogene DDX12p. Importantly, G-quadruplex (G4) stabilizing compounds induce chromosome breaks and cohesion defects which are strongly aggravated by inactivation of DDX11 but not FANCJ. The DNA helicase domain of DD

The Carbohydrate-Binding Site in Galectin-3 Is Preorganized To Recognize a Sugarlike Framework of Oxygens: Ultra-High-Resolution Structures and Water Dynamics

The recognition of carbohydrates by proteins is a fundamental aspect of communication within and between living cells. Understanding the molecular basis of carbohydrate-protein interactions is a prerequisite for the rational design of synthetic ligands. Here we report the high- to ultrahigh-resolution crystal structures of the carbohydrate recognition domain of galectin-3 (Gal3C) in the ligand-free state (1.08 angstrom at 100 K, 1.25 angstrom at 298 K) and in complex with lactose (0.86 angstrom) or glycerol (0.9 angstrom). These structures reveal striking similarities in the positions of water and carbohydrate oxygen atoms in all three states, indicating that the binding site of Gal3C is preorganized to coordinate oxygen atoms in an arrangement that is nearly optimal for the recognition of beta-galactosides. Deuterium nuclear magnetic resonance (NMR) relaxation dispersion experiments and molecular dynamics simulations demonstrate that all water molecules in the lactose-binding site exchange with bulk water on a time scale of nanoseconds or shorter. Nevertheless, molecular dynamics simulations identify transient water binding at sites that agree well with those observed by crystallography, indicating that the energy landscape of the binding site is maintained in solution. All heavy atoms of glycerol are positioned like the corresponding atoms of lactose in the Gal3C complexes. However, binding of glycerol to Gal3C is insignificant in solution at room temperature, as monitored by NMR spectroscopy or isothermal titration calorimetry under conditions where lactose binding is readily detected. These observations make a case for protein cryo-crystallography as a valuable screening method in fragment-based drug discovery and further suggest that identification of water sites might inform inhibitor design

The Use of Wavelets in Image Interpolation: Possibilities and Limitations

Discrete wavelet transform (DWT) can be used in various applications, such as image compression and coding. In this paper we examine how DWT can be used in image interpolation. Afterwards proposed method is compared with two other traditional interpolation methods. For the case of magnified image achieved by interpolation, original image is unknown and there is no perfect way to judge the magnification quality. Common approach is to start with an original image, generate a lower resolution version of original image by downscaling, and then use different interpolation methods to magnify low resolution image. After that original and magnified images are compared to evaluate difference between them using different picture quality measures. Our results show that comparison of image interpolation methods depends on downscaling technique, image contents and quality metric. For fair comparison all these parameters need to be considered

3D Video Tools

This chapter presents an overview of different tools used in research and engineering of 3D video delivery systems. These include software tools for 3D video compression and streaming, 3D video players, and their interfaces. Other types of tools widely used in research studies and development of new networking solutions, such as network simulators, emulators, testbeds, and network analysis tools are also covered. In addition, several 3D video evaluation tools, which have been specifically designed for testing and evaluation of 3D video sequences subject to network impairments, are further described. The chapter also presents several examples of recent works that have been carried out based on one or more simulation, emulation, test, and/or evaluation tools in research studies or innovative solutions for relevant problems affecting 3D multimedia delivery

Point cloud visualization methods: A study on subjective preferences

The availability of 3D range scanners and RGB-D cameras is pushing the spreading of point cloud-based applications. One of the main issues of this technology, in applications where the end user is a human observer, is the presentation of the data. Three-dimensional visual information represented as point clouds can be displayed in several ways, e.g. as sets of points with varying point size or as a surface rendered using one of several available methods, such as Poisson surface interpolation. Furthermore, to increase the feeling of presence, or immersiveness, novel hardware can be used such as 3D displays and head mounted devices. However, even if 3D-able visualization devices are available, common users are more accustomed to observing visual information displayed on a 2D screen and it is not clear which combination of presentation method and device are preferred by the users. In this contribution we assess the user preference of visualization of point clouds in terms of different rendering devices and methods. A set of subjective experiments is performed, involving point clouds presented as points or rendered surfaces displayed in 2D and 3D displays. The results obtained were analysed to measure user preferences