26,803 research outputs found
De Bruijn Structured Illumination Studying Within The Task Of Restoring Hands Relief
In the course of studies on the problem of restoring hands relief, using the de Bruijn structured illumination, methods of solving this problem are proposed. This is a method of simple quantitative detection of Hough segments on the skin of the hand, a method of qualitative visual evaluation of the effectiveness of the color palette using the dominant color, and a method of the weight coefficients of the components of the color palette.The proposed methods make it possible to quantitatively determine the optimal choice of the color scheme for generating the de Bruijn bands when illumination of the hand, to restore its relief.The work describes the stages of this study, led from visual observation to a full quantitative calculation of the quality of calibration illuminations, with the possibility of their optimal choice.In the course of experiments and observations, the requirements for the technical support of research were developed to achieve the best quality of the images of the hands. Also, the paper presents a high-speed de Bruijn sequence generating algorithm using Lyndon's words, which excludes the search for Euler chains or Hamiltonian cycles, for various kinds of de Bruijn graphs. With its help, the generation of structured light patterns with various color schemes was carried out, with the purpose of further analysis of their use in 3D reconstruction systems of hands
Online Feature Selection for Visual Tracking
Object tracking is one of the most important tasks in many applications of computer vision. Many tracking methods use a fixed set of features ignoring that appearance of a target object may change drastically due to intrinsic and extrinsic factors. The ability to dynamically identify discriminative features would help in handling the appearance variability by improving tracking performance. The contribution of this work is threefold. Firstly, this paper presents a collection of several modern feature selection approaches selected among filter, embedded, and wrapper methods. Secondly, we provide extensive tests regarding the classification task intended to explore the strengths and weaknesses of the proposed methods with the goal to identify the right candidates for online tracking. Finally, we show how feature selection mechanisms can be successfully employed for ranking the features used by a tracking system, maintaining high frame rates. In particular, feature selection mounted on the Adaptive Color Tracking (ACT) system operates at over 110 FPS. This work demonstrates the importance of feature selection in online and realtime applications, resulted in what is clearly a very impressive performance, our solutions improve by 3% up to 7% the baseline ACT while providing superior results compared to 29 state-of-the-art tracking methods
Long-term photometric and spectroscopic observations of the near-contact binary KR Cygni
We present the multi-color, five-year light curves and the first radial
velocities of the near-contact binary system KR Cyg. We derived the masses of
the components as 2.880.20 M and 1.260.07 M and
the radii as 2.590.06 R and 1.800.04 R. Analyses
of the UBVR light curves and the radial velocities indicate that none of the
components exactly fill their corresponding Roche lobes. We have calculated the
distance to the system of KR Cyg as {41112} pc using the observed apparent
UBV magnitudes and the bolometric corrections for the component stars. We also
searched for the empirical determination of albedo and effective temperature of
the cooler, less massive star of KR Cyg, and of two similar near contact
binaries AK CMi, and DO Cas. The residuals between the observed and computed
fluxes are attributed to the effect of mutual illumination which heats the
surface layers of the illuminated star and does vary not only its bolometric
albedo but also its limb-darkening coefficient and gravity-brightening
exponent. The analysis of the light curves shows that the effective albedos are
generally smaller than that expected from an envelope of convective star, being
mostly departed from the theoretical value at the B passband. As the reflected
light diminishes the effective temperature and, therefore, the luminosity of
the irradiated star increase. The observed bluer U-B colors during primary
minimum are attributed to the effects of mutual irradiation and multiple
scattering processes which may alter several characteristics of these systems.Comment: Accepted. 18 pages, 7 figures; 2012, October, Rev. Me
Learning Compositional Visual Concepts with Mutual Consistency
Compositionality of semantic concepts in image synthesis and analysis is
appealing as it can help in decomposing known and generatively recomposing
unknown data. For instance, we may learn concepts of changing illumination,
geometry or albedo of a scene, and try to recombine them to generate physically
meaningful, but unseen data for training and testing. In practice however we
often do not have samples from the joint concept space available: We may have
data on illumination change in one data set and on geometric change in another
one without complete overlap. We pose the following question: How can we learn
two or more concepts jointly from different data sets with mutual consistency
where we do not have samples from the full joint space? We present a novel
answer in this paper based on cyclic consistency over multiple concepts,
represented individually by generative adversarial networks (GANs). Our method,
ConceptGAN, can be understood as a drop in for data augmentation to improve
resilience for real world applications. Qualitative and quantitative
evaluations demonstrate its efficacy in generating semantically meaningful
images, as well as one shot face verification as an example application.Comment: 10 pages, 8 figures, 4 tables, CVPR 201
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