22 research outputs found
The World of Fast Moving Objects
The notion of a Fast Moving Object (FMO), i.e. an object that moves over a
distance exceeding its size within the exposure time, is introduced. FMOs may,
and typically do, rotate with high angular speed. FMOs are very common in
sports videos, but are not rare elsewhere. In a single frame, such objects are
often barely visible and appear as semi-transparent streaks.
A method for the detection and tracking of FMOs is proposed. The method
consists of three distinct algorithms, which form an efficient localization
pipeline that operates successfully in a broad range of conditions. We show
that it is possible to recover the appearance of the object and its axis of
rotation, despite its blurred appearance. The proposed method is evaluated on a
new annotated dataset. The results show that existing trackers are inadequate
for the problem of FMO localization and a new approach is required. Two
applications of localization, temporal super-resolution and highlighting, are
presented
H-NeXt: The next step towards roto-translation invariant networks
The widespread popularity of equivariant networks underscores the
significance of parameter efficient models and effective use of training data.
At a time when robustness to unseen deformations is becoming increasingly
important, we present H-NeXt, which bridges the gap between equivariance and
invariance. H-NeXt is a parameter-efficient roto-translation invariant network
that is trained without a single augmented image in the training set. Our
network comprises three components: an equivariant backbone for learning
roto-translation independent features, an invariant pooling layer for
discarding roto-translation information, and a classification layer. H-NeXt
outperforms the state of the art in classification on unaugmented training sets
and augmented test sets of MNIST and CIFAR-10.Comment: Appears in British Machine Vision Conference 2023 (BMVC 2023
Sub-frame Appearance and 6D Pose Estimation of Fast Moving Objects
We propose a novel method that tracks fast moving objects, mainly non-uniform
spherical, in full 6 degrees of freedom, estimating simultaneously their 3D
motion trajectory, 3D pose and object appearance changes with a time step that
is a fraction of the video frame exposure time. The sub-frame object
localization and appearance estimation allows realistic temporal
super-resolution and precise shape estimation. The method, called TbD-3D
(Tracking by Deblatting in 3D) relies on a novel reconstruction algorithm which
solves a piece-wise deblurring and matting problem. The 3D rotation is
estimated by minimizing the reprojection error. As a second contribution, we
present a new challenging dataset with fast moving objects that change their
appearance and distance to the camera. High speed camera recordings with zero
lag between frame exposures were used to generate videos with different frame
rates annotated with ground-truth trajectory and pose
NeRD: Neural field-based Demosaicking
We introduce NeRD, a new demosaicking method for generating full-color images
from Bayer patterns. Our approach leverages advancements in neural fields to
perform demosaicking by representing an image as a coordinate-based neural
network with sine activation functions. The inputs to the network are spatial
coordinates and a low-resolution Bayer pattern, while the outputs are the
corresponding RGB values. An encoder network, which is a blend of ResNet and
U-net, enhances the implicit neural representation of the image to improve its
quality and ensure spatial consistency through prior learning. Our experimental
results demonstrate that NeRD outperforms traditional and state-of-the-art
CNN-based methods and significantly closes the gap to transformer-based
methods.Comment: 5 pages, 4 figures, 1 tabl
Blur Invariants for Image Recognition
Blur is an image degradation that is difficult to remove. Invariants with
respect to blur offer an alternative way of a~description and recognition of
blurred images without any deblurring. In this paper, we present an original
unified theory of blur invariants. Unlike all previous attempts, the new theory
does not require any prior knowledge of the blur type. The invariants are
constructed in the Fourier domain by means of orthogonal projection operators
and moment expansion is used for efficient and stable computation. It is shown
that all blur invariants published earlier are just particular cases of this
approach. Experimental comparison to concurrent approaches shows the advantages
of the proposed theory.Comment: 15 page
Real-Time Wheel Detection and Rim Classification in Automotive Production
This paper proposes a novel approach to real-time automatic rim detection,
classification, and inspection by combining traditional computer vision and
deep learning techniques. At the end of every automotive assembly line, a
quality control process is carried out to identify any potential defects in the
produced cars. Common yet hazardous defects are related, for example, to
incorrectly mounted rims. Routine inspections are mostly conducted by human
workers that are negatively affected by factors such as fatigue or distraction.
We have designed a new prototype to validate whether all four wheels on a
single car match in size and type. Additionally, we present three comprehensive
open-source databases, CWD1500, WHEEL22, and RB600, for wheel, rim, and bolt
detection, as well as rim classification, which are free-to-use for scientific
purposes.Comment: 5 pages, 7 figures, 3 table
Relationship between remnant hippocampus and amygdala and memory outcomes after stereotactic surgery for mesial temporal lobe epilepsy
Temporal Ordering in Endocytic Clathrin-Coated Vesicle Formation via AP2 Phosphorylation.
Clathrin-mediated endocytosis (CME) is key to maintaining the transmembrane protein composition of cells' limiting membranes. During mammalian CME, a reversible phosphorylation event occurs on Thr156 of the μ2 subunit of the main endocytic clathrin adaptor, AP2. We show that this phosphorylation event starts during clathrin-coated pit (CCP) initiation and increases throughout CCP lifetime. μ2Thr156 phosphorylation favors a new, cargo-bound conformation of AP2 and simultaneously creates a binding platform for the endocytic NECAP proteins but without significantly altering AP2's cargo affinity in vitro. We describe the structural bases of both. NECAP arrival at CCPs parallels that of clathrin and increases with μ2Thr156 phosphorylation. In turn, NECAP recruits drivers of late stages of CCP formation, including SNX9, via a site distinct from where NECAP binds AP2. Disruption of the different modules of this phosphorylation-based temporal regulatory system results in CCP maturation being delayed and/or stalled, hence impairing global rates of CME
Influence of Treatment With Tumor-Treating Fields on Health-Related Quality of Life of Patients With Newly Diagnosed Glioblastoma: A Secondary Analysis of a Randomized Clinical Trial
Importance Tumor-treating fields (TTFields) therapy improves both progression-free and overall survival in patients with glioblastoma. There is a need to assess the influence of TTFields on patients' health-related quality of life (HRQoL).
Objective To examine the association of TTFields therapy with progression-free survival and HRQoL among patients with glioblastoma.
Design, Setting, and Participants This secondary analysis of EF-14, a phase 3 randomized clinical trial, compares TTFields and temozolomide or temozolomide alone in 695 patients with glioblastoma after completion of radiochemotherapy. Patients with glioblastoma were randomized 2:1 to combined treatment with TTFields and temozolomide or temozolomide alone. The study was conducted from July 2009 until November 2014, and patients were followed up through December 2016.
Interventions Temozolomide, 150 to 200 mg/m2/d, was given for 5 days during each 28-day cycle. TTFields were delivered continuously via 4 transducer arrays placed on the shaved scalp of patients and were connected to a portable medical device.
Main Outcomes and Measures Primary study end point was progression-free survival; HRQoL was a predefined secondary end point, measured with questionnaires at baseline and every 3 months thereafter. Mean changes from baseline scores were evaluated, as well as scores over time. Deterioration-free survival and time to deterioration were assessed for each of 9 preselected scales and items.
Results Of the 695 patients in the study, 639 (91.9%) completed the baseline HRQoL questionnaire. Of these patients, 437 (68.4%) were men; mean (SD) age, 54.8 (11.5) years. Health-related quality of life did not differ significantly between treatment arms except for itchy skin. Deterioration-free survival was significantly longer with TTFields for global health (4.8 vs 3.3 months; P < .01); physical (5.1 vs 3.7 months; P < .01) and emotional functioning (5.3 vs 3.9 months; P < .01); pain (5.6 vs 3.6 months; P < .01); and leg weakness (5.6 vs 3.9 months; P < .01), likely related to improved progression-free survival. Time to deterioration, reflecting the influence of treatment, did not differ significantly except for itchy skin (TTFields worse; 8.2 vs 14.4 months; P < .001) and pain (TTFields improved; 13.4 vs 12.1 months; P < .01). Role, social, and physical functioning were not affected by TTFields.
Conclusions and Relevance The addition of TTFields to standard treatment with temozolomide for patients with glioblastoma results in improved survival without a negative influence on HRQoL except for more itchy skin, an expected consequence from the transducer arrays.
Trial Registration clinicaltrials.gov Identifier: NCT00916409
Ruptured Thoracolumbar Perimedullary Arteriovenous Fistula during Pregnancy Complicated by Cerebral Subarachnoid Hemorrhage and Brainstem Hematoma: A Case Report
Intradural spinal arteriovenous fistulas (sAVF) are spinal vascular lesions that usually manifest due to myelopathy or local symptoms caused by venous congestion and ischemia. In addition, perimedullary arteriovenous fistulas (PMAVF) in particular may rupture and cause subarachnoid or intramedullary hemorrhage along with relevant symptoms. Subarachnoid hemorrhage (SAH) can propagate into cranial space with clinically dominant symptoms and signs of typical aneurysmal intracranial SAH. The standard workup for cerebral SAH, after excluding an intracranial source of hemorrhage, is usually limited to a cervical spine MRI; therefore, thoracolumbar sources of hemorrhage can be missed, or their diagnosis may be delayed. Here we present a case of a pregnant patient who presented with cerebral SAH. The source of hemorrhage was not initially identified, leading to a presumptive diagnosis of benign pretruncal non-aneurysmal SAH. The correct diagnosis of spinal thoracolumbar PMAVF was revealed 2.5 months later due to the progression of local symptoms. While the diagnosis was being refined and endovascular treatment was being planned (but delayed due to pregnancy), there was a recurrence of intraconal hemorrhage followed by brainstem hemorrhage. This led to significant clinical deterioration. The PMAVF was then treated microsurgically and the patient experienced partial recovery