Search results for "distortion"
showing 10 items of 309 documents
Mesh Visual Quality based on the combination of convolutional neural networks
2019
Blind quality assessment is a challenging issue since the evaluation is done without access to the reference nor any information about the distortion. In this work, we propose an objective blind method for the visual quality assessment of 3D meshes. The method estimates the perceived visual quality using only information from the distorted mesh to feed pre-trained deep convolutional neural networks. The input data is prepared by rendering 2D views from the 3D mesh and the corresponding saliency map. The views are split into small patches of fixed size that are filtered using a saliency threshold. Only the salient patches are selected as input data. After that, three pre-trained deep convolu…
Target tracking with dynamically adaptive correlation
2016
Abstract A reliable algorithm for target tracking based on dynamically adaptive correlation filtering is presented. The algorithm is capable of tracking with high accuracy the location of a target in an input video sequence without using an offline training process. The target is selected at the beginning of the algorithm. Afterwards, a composite correlation filter optimized for distortion tolerant pattern recognition is designed to recognize the target in the next frame. The filter is dynamically adapted to each frame using information of current and past scene observations. Results obtained with the proposed algorithm in synthetic and real-life video sequences, are analyzed and compared w…
Application Of Anamorphic Systems To Directional Pseudocolor Encoding
1988
An optical nonsymmetrical imaging system composed of two anamorphic spectrum analyzers in cascade is implemented. This system can provide an undistorted final image in spite of the geometrical distortion effects in the intermediate Fourier plane. The introduction of chromatic sector filters in this plane provides a real-time technique to pseudocolor encode the spatial frequency information of a black-and-white transparency. In this way, greater discrimination is achieved in the angular orientation of object details that generate the same spatial frequencies. Experimental pseudocolored images, obtained with a symmetrical system and a nonsymmetrical system, of a black-and-white transparency a…
Remote Sensing Geometric Corrections
2016
This article reviews the different aspects of geometrical processing of remote sensing data, discussing error sources and methods to determine the transformation from the image acquisition geometry to the output cartographic product. Resampling methods are discussed to transform the input image to the output geometry. Several practical examples of remote sensing platforms are discussed, including satellite cases and airborne sensors. Validation of the resulting geometrical processed products is also discussed. Spatial mosaicking techniques and multitemporal composites used to produce multisource integrated products and advanced applications are finally considered, keeping a perspective on t…
Visual Cortex Performs a Sort of Non-linear ICA
2010
Here, the standard V1 cortex model optimized to reproduce image distortion psychophysics is shown to have nice statistical properties, e.g. approximate factorization of the PDF of natural images. These results confirm the efficient encoding hypothesis that aims to explain the organization of biological sensors by information theory arguments.
Sharpness of the differentiability almost everywhere and capacitary estimates for Sobolev mappings
2017
We give sharp conformal conditions for the dfferentiability in the Sobolev space W1, n-1 loc (Ω,Rn). Furthermore, we show that the space W1, n-1 loc (Ω,Rn) can be considered as the borderline space for some capacitary inequalities. peerReviewed
Dependence of the distortion of the square pyramids in N,N-dimethylethylenediammonium pentachloroantimonate(III) on the geometry of hydrogen bonds
2001
Abstract N ,N-Dimethylethylenediammonium pentachloroantimonate(III) crystallizes in the monoclinic system, in space group P21/c (a = 12.460(2), b = 10.252(2), c = 10.330(2) Å, β = 97.75(3)°, V = 1307.5(4) Å3, Z = 4, dc = 1.997, dm = 1.99(2) g/cm3). The crystal structure of [(CH3)2NH(CH2)2NH3][SbCl5] consists of isolated [SbCl5]2- anions and [(CH3)2NH(CH2)2NH3]2+ cations. The [SbCl5]2- anion has a distorted square pyramidal geometry, presenting one short axial and four long equatorial Sb-Cl bonds. The square pyramids are characteristically stacked one close to the other, parallel to the c axis. The voids between the anionic sublattice are filled by [(CH3)2NH(CH2)2NH3]2+ cations. The five non…
Phase transitions and distortion of [BiCl6]3– octahedra in (C3H5NH3)3[BiCl6] – DSC and single-crystal X-Ray diffraction studies
2004
The DSC diagram of tris(allylammonium) hexachlorobismuthate(III), (C3H5NH3)3[BiCl6], revealed three anomalies at 152, 191 and 299 K. The structure of the salt was determined at 200 and 315 K, below and above the high-temperature phase transition at 299 K. In both phases the crystals are monoclinic. At 200 K the space group is C2/c whereas at 315 K it is C2/m. The structures, at both temperatures, are composed of [BiCl6]3− octahedra and allylammonium cations. The organic and inorganic moieties are attracted to each other by a network of the N-H. . .Cl hydrogen bonds. The relationship between corresponding parameters of the unit cells has been found. The phase transition at 299 K, of the orde…
Hating Adolescents Test (HAT): a preliminary development of a measure to assess hating among adolescents
2020
The phenomenon of haters is becoming common among adolescents. The aims of the present research were to evaluate the preliminary psychometric properties of the Hating Adolescents Test (HAT), an ad hoc questionnaire created to evaluate online and offline hate (Study 1), and possible risk factors connected with hate (Study 2). Participants (202 female and 200 male) of this study completed the HAT, the How I Think Questionnaire, the Buss–Perry Aggression Questionnaire, and the Penn State Worry Questionnaire. Descriptive statistics were calculated, and exploratory factor analysis and confirmatory factor analysis were applied. Preliminary data suggest how males reported higher level of hate than…
Kognitīvo izkropļojumu saistība ar pārbaudījumu trauksmi un akadēmisko pašefektivitāti studentiem
2019
Pētījuma mērķis bija noskaidrot, kādas ir kognitīvo izkropļojumu, pārbaudījumu trauksmes un akadēmiskās pašefektivitātes savstarpējās saistības studentu vidū un vai vērojamas atšķirības mainīgo saistībās sieviešu un vīriešu izlasēs, kā arī noskaidrot atšķirības pārbaudījumu trauksmes un akadēmisko pašefektivitātes rādītājos dažādos studiju kursos un noteikt kādā mērā kognitīvo izkropļojumu izteiktība prognozē pārbaudījumu trauksmi un akadēmisko pašefektivitāti studentiem. Pētījumā piedalījās 116 šobrīd studējoši studenti (74 sievietes) vecumā no 18-29 gadiem. Vidējais vecums izlasē bija 22,72 gadi (SD= 2,42). Dati tika ievākti interneta vidē, publicējot aptaujas tiešsaistes piekļuvi sociāla…