19,897 research outputs found
Optical synthesizer for a large quadrant-array CCD camera: Center director's discretionary fund
The objective of this program was to design and develop an optical device, an optical synthesizer, that focuses four contiguous quadrants of a solar image on four spatially separated CCD arrays that are part of a unique CCD camera system. This camera and the optical synthesizer will be part of the new NASA-Marshall Experimental Vector Magnetograph, and instrument developed to measure the Sun's magnetic field as accurately as present technology allows. The tasks undertaken in the program are outlined and the final detailed optical design is presented
How to Make an Image More Memorable? A Deep Style Transfer Approach
Recent works have shown that it is possible to automatically predict
intrinsic image properties like memorability. In this paper, we take a step
forward addressing the question: "Can we make an image more memorable?".
Methods for automatically increasing image memorability would have an impact in
many application fields like education, gaming or advertising. Our work is
inspired by the popular editing-by-applying-filters paradigm adopted in photo
editing applications, like Instagram and Prisma. In this context, the problem
of increasing image memorability maps to that of retrieving "memorabilizing"
filters or style "seeds". Still, users generally have to go through most of the
available filters before finding the desired solution, thus turning the editing
process into a resource and time consuming task. In this work, we show that it
is possible to automatically retrieve the best style seeds for a given image,
thus remarkably reducing the number of human attempts needed to find a good
match. Our approach leverages from recent advances in the field of image
synthesis and adopts a deep architecture for generating a memorable picture
from a given input image and a style seed. Importantly, to automatically select
the best style a novel learning-based solution, also relying on deep models, is
proposed. Our experimental evaluation, conducted on publicly available
benchmarks, demonstrates the effectiveness of the proposed approach for
generating memorable images through automatic style seed selectionComment: Accepted at ACM ICMR 201
Relating Objective and Subjective Performance Measures for AAM-based Visual Speech Synthesizers
We compare two approaches for synthesizing visual speech using Active Appearance Models (AAMs): one that utilizes acoustic features as input, and one that utilizes a phonetic transcription as input. Both synthesizers are trained using the same data and the performance is measured using both objective and subjective testing. We investigate the impact of likely sources of error in the synthesized visual speech by introducing typical errors into real visual speech sequences and subjectively measuring the perceived degradation. When only a small region (e.g. a single syllable) of ground-truth visual speech is incorrect we find that the subjective score for the entire sequence is subjectively lower than sequences generated by our synthesizers. This observation motivates further consideration of an often ignored issue, which is to what extent are subjective measures correlated with objective measures of performance? Significantly, we find that the most commonly used objective measures of performance are not necessarily the best indicator of viewer perception of quality. We empirically evaluate alternatives and show that the cost of a dynamic time warp of synthesized visual speech parameters to the respective ground-truth parameters is a better indicator of subjective quality
Multicascade-linked synthetic wavelength digital holography using an optical-comb-referenced frequency synthesizer
Digital holography (DH) is a promising method for non-contact surface
topography because the reconstructed phase image can visualize the nanometer
unevenness in a sample. However, the axial range of this method is limited to
the range of the optical wavelength due to the phase wrapping ambiguity.
Although the use of two different wavelengths of light and the resulting
synthetic wavelength, i.e., synthetic wavelength DH, can expand the axial range
up to a few tens of microns, this method is still insufficient for practical
applications. In this article, a tunable external cavity laser diode
phase-locked to an optical frequency comb, namely, an optical-comb-referenced
frequency synthesizer, is effectively used for multiple synthetic wavelengths
within the range of 32 um to 1.20 m. A multiple cascade link of the phase
images among an optical wavelength (= 1.520 um) and 5 different synthetic
wavelengths (= 32.39 um, 99.98 um, 400.0 um, 1003 um, and 4021 um) enables the
shape measurement of a reflective millimeter-sized stepped surface with the
axial resolution of 34 nm. The axial dynamic range, defined as the ratio of the
maximum axial range (= 0.60 m) to the axial resolution (= 34 nm), achieves
1.7*10^8, which is much larger than that of previous synthetic wavelength DH.
Such a wide axial dynamic range capability will further expand the application
field of DH for large objects with meter dimensions.Comment: 19 pages, 7 figure
Self-Supervised Audio-Visual Co-Segmentation
Segmenting objects in images and separating sound sources in audio are
challenging tasks, in part because traditional approaches require large amounts
of labeled data. In this paper we develop a neural network model for visual
object segmentation and sound source separation that learns from natural videos
through self-supervision. The model is an extension of recently proposed work
that maps image pixels to sounds. Here, we introduce a learning approach to
disentangle concepts in the neural networks, and assign semantic categories to
network feature channels to enable independent image segmentation and sound
source separation after audio-visual training on videos. Our evaluations show
that the disentangled model outperforms several baselines in semantic
segmentation and sound source separation.Comment: Accepted to ICASSP 201
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