38 research outputs found
Combining Stereo Disparity and Optical Flow for Basic Scene Flow
Scene flow is a description of real world motion in 3D that contains more
information than optical flow. Because of its complexity there exists no
applicable variant for real-time scene flow estimation in an automotive or
commercial vehicle context that is sufficiently robust and accurate. Therefore,
many applications estimate the 2D optical flow instead. In this paper, we
examine the combination of top-performing state-of-the-art optical flow and
stereo disparity algorithms in order to achieve a basic scene flow. On the
public KITTI Scene Flow Benchmark we demonstrate the reasonable accuracy of the
combination approach and show its speed in computation.Comment: Commercial Vehicle Technology Symposium (CVTS), 201
SceneFlowFields: Dense Interpolation of Sparse Scene Flow Correspondences
While most scene flow methods use either variational optimization or a strong
rigid motion assumption, we show for the first time that scene flow can also be
estimated by dense interpolation of sparse matches. To this end, we find sparse
matches across two stereo image pairs that are detected without any prior
regularization and perform dense interpolation preserving geometric and motion
boundaries by using edge information. A few iterations of variational energy
minimization are performed to refine our results, which are thoroughly
evaluated on the KITTI benchmark and additionally compared to state-of-the-art
on MPI Sintel. For application in an automotive context, we further show that
an optional ego-motion model helps to boost performance and blends smoothly
into our approach to produce a segmentation of the scene into static and
dynamic parts.Comment: IEEE Winter Conference on Applications of Computer Vision (WACV),
201
Broad Absorption Line Quasar catalogues with Supervised Neural Networks
We have applied a Learning Vector Quantization (LVQ) algorithm to SDSS DR5
quasar spectra in order to create a large catalogue of broad absorption line
quasars (BALQSOs). We first discuss the problems with BALQSO catalogues
constructed using the conventional balnicity and/or absorption indices (BI and
AI), and then describe the supervised LVQ network we have trained to recognise
BALQSOs. The resulting BALQSO catalogue should be substantially more robust and
complete than BI- or AI-based ones.Comment: 5 pages, 3 figures, to appear in the proceedings of "Classification
and Discovery in Large Astronomical Surveys", Ringberg Castle, 14-17 October
200
Fast View Synthesis with Deep Stereo Vision
Novel view synthesis is an important problem in computer vision and graphics.
Over the years a large number of solutions have been put forward to solve the
problem. However, the large-baseline novel view synthesis problem is far from
being "solved". Recent works have attempted to use Convolutional Neural
Networks (CNNs) to solve view synthesis tasks. Due to the difficulty of
learning scene geometry and interpreting camera motion, CNNs are often unable
to generate realistic novel views. In this paper, we present a novel view
synthesis approach based on stereo-vision and CNNs that decomposes the problem
into two sub-tasks: view dependent geometry estimation and texture inpainting.
Both tasks are structured prediction problems that could be effectively learned
with CNNs. Experiments on the KITTI Odometry dataset show that our approach is
more accurate and significantly faster than the current state-of-the-art. The
code and supplementary material will be publicly available. Results could be
found here https://youtu.be/5pzS9jc-5t
Innate PD-L1 limits T cell–mediated adipose tissue inflammation and ameliorates diet-induced obesity
Obesity has become a major health problem in the industrialized world. Immune regulation plays an important role in adipose tissue homeostasis; however, the initial events that shift the balance from a noninflammatory homeostatic environment toward inflammation leading to obesity are poorly understood. Here, we report a role for the costimulatory molecule programmed death-ligand 1 (PD-L1) in the limitation of diet-induced obesity. Functional ablation of PD-L1 on dendritic cells (DCs) using conditional knockout mice increased weight gain and metabolic syndrome during diet-induced obesity, whereas PD-L1 expression on type 2 innate lymphoid cells (ILC2s), T cells, and macrophages was dispensable for obesity control. Using in vitro cocultures, DCs interacted with T cells and ILC2s via the PD-L1:PD-1 axis to inhibit T helper type 1 proliferation and promote type 2 polarization, respectively. A role for PD-L1 in adipose tissue regulation was also shown in humans, with a positive correlation between PD-L1 expression in visceral fat of people with obesity and elevated body weight. Thus, we define a mechanism of adipose tissue homeostasis controlled by the expression of PD-L1 by DCs, which may be a clinically relevant finding with regard to immune-related adverse events during immune checkpoint inhibitor therapy