13,965 research outputs found
Unobtrusive and pervasive video-based eye-gaze tracking
Eye-gaze tracking has long been considered a desktop technology that finds its use inside the traditional office setting, where the operating conditions may be controlled. Nonetheless, recent advancements in mobile technology and a growing interest in capturing natural human behaviour have motivated an emerging interest in tracking eye movements within unconstrained real-life conditions, referred to as pervasive eye-gaze tracking. This critical review focuses on emerging passive and unobtrusive video-based eye-gaze tracking methods in recent literature, with the aim to identify different research avenues that are being followed in response to the challenges of pervasive eye-gaze tracking. Different eye-gaze tracking approaches are discussed in order to bring out their strengths and weaknesses, and to identify any limitations, within the context of pervasive eye-gaze tracking, that have yet to be considered by the computer vision community.peer-reviewe
Visible spectrum extended-focus optical coherence microscopy for label-free sub-cellular tomography
We present a novel extended-focus optical coherence microscope (OCM)
attaining 0.7 {\mu}m axial and 0.4 {\mu}m lateral resolution maintained over a
depth of 40 {\mu}m, while preserving the advantages of Fourier domain OCM. Our
method uses an ultra-broad spectrum from a super- continuum laser source. As
the spectrum spans from near-infrared to visible wavelengths (240 nm in
bandwidth), we call the method visOCM. The combination of such a broad spectrum
with a high-NA objective creates an almost isotropic 3D submicron resolution.
We analyze the imaging performance of visOCM on microbead samples and
demonstrate its image quality on cell cultures and ex-vivo mouse brain tissue.Comment: 15 pages, 7 figure
Self-supervised Multi-level Face Model Learning for Monocular Reconstruction at over 250 Hz
The reconstruction of dense 3D models of face geometry and appearance from a
single image is highly challenging and ill-posed. To constrain the problem,
many approaches rely on strong priors, such as parametric face models learned
from limited 3D scan data. However, prior models restrict generalization of the
true diversity in facial geometry, skin reflectance and illumination. To
alleviate this problem, we present the first approach that jointly learns 1) a
regressor for face shape, expression, reflectance and illumination on the basis
of 2) a concurrently learned parametric face model. Our multi-level face model
combines the advantage of 3D Morphable Models for regularization with the
out-of-space generalization of a learned corrective space. We train end-to-end
on in-the-wild images without dense annotations by fusing a convolutional
encoder with a differentiable expert-designed renderer and a self-supervised
training loss, both defined at multiple detail levels. Our approach compares
favorably to the state-of-the-art in terms of reconstruction quality, better
generalizes to real world faces, and runs at over 250 Hz.Comment: CVPR 2018 (Oral). Project webpage:
https://gvv.mpi-inf.mpg.de/projects/FML
Shedding Light on Diatom Photonics by means of Digital Holography
Diatoms are among the dominant phytoplankters in the worl's ocean, and their
external silica investments, resembling artificial photonics crystal, are
expected to play an active role in light manipulation. Digital holography
allowed studying the interaction with light of Coscinodiscus wailesii cell wall
reconstructing the light confinement inside the cell cytoplasm, condition that
is hardly accessible via standard microscopy. The full characterization of the
propagated beam, in terms of quantitative phase and intensity, removed a
long-standing ambiguity about the origin of the light. The data were discussed
in the light of living cell behavior in response to their environment
A Novel Framework for Highlight Reflectance Transformation Imaging
We propose a novel pipeline and related software tools for processing the multi-light image collections (MLICs) acquired in different application contexts to obtain shape and appearance information of captured surfaces, as well as to derive compact relightable representations of them. Our pipeline extends the popular Highlight Reflectance Transformation Imaging (H-RTI) framework, which is widely used in the Cultural Heritage domain. We support, in particular, perspective camera modeling, per-pixel interpolated light direction estimation, as well as light normalization correcting vignetting and uneven non-directional illumination. Furthermore, we propose two novel easy-to-use software tools to simplify all processing steps. The tools, in addition to support easy processing and encoding of pixel data, implement a variety of visualizations, as well as multiple reflectance-model-fitting options. Experimental tests on synthetic and real-world MLICs demonstrate the usefulness of the novel algorithmic framework and the potential benefits of the proposed tools for end-user applications.Terms: "European Union (EU)" & "Horizon 2020" / Action: H2020-EU.3.6.3. - Reflective societies - cultural heritage and European identity / Acronym: Scan4Reco / Grant number: 665091DSURF project (PRIN 2015) funded by the Italian Ministry of University and ResearchSardinian Regional Authorities under projects VIGEC and Vis&VideoLa
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