472 research outputs found
Recaptured Raw Screen Image and Video Demoir\'eing via Channel and Spatial Modulations
Capturing screen contents by smartphone cameras has become a common way for
information sharing. However, these images and videos are often degraded by
moir\'e patterns, which are caused by frequency aliasing between the camera
filter array and digital display grids. We observe that the moir\'e patterns in
raw domain is simpler than those in sRGB domain, and the moir\'e patterns in
raw color channels have different properties. Therefore, we propose an image
and video demoir\'eing network tailored for raw inputs. We introduce a
color-separated feature branch, and it is fused with the traditional
feature-mixed branch via channel and spatial modulations. Specifically, the
channel modulation utilizes modulated color-separated features to enhance the
color-mixed features. The spatial modulation utilizes the feature with large
receptive field to modulate the feature with small receptive field. In
addition, we build the first well-aligned raw video demoir\'eing
(RawVDemoir\'e) dataset and propose an efficient temporal alignment method by
inserting alternating patterns. Experiments demonstrate that our method
achieves state-of-the-art performance for both image and video demori\'eing. We
have released the code and dataset in https://github.com/tju-chengyijia/VD_raw
Simulation-based transition density approximation for the inference of SDE models
Stochastic Differential Equations (SDEs) serve as a powerful modeling tool in
various scientific domains, including systems science, engineering, and
ecological science. While the specific form of SDEs is typically known for a
given problem, certain model parameters remain unknown. Efficiently inferring
these unknown parameters based on observations of the state in discrete time
series represents a vital practical subject. The challenge arises in nonlinear
SDEs, where maximum likelihood estimation of parameters is generally unfeasible
due to the absence of closed-form expressions for transition and stationary
probability density functions of the states. In response to this limitation, we
propose a novel two-step parameter inference mechanism. This approach involves
a global-search phase followed by a local-refining procedure. The global-search
phase is dedicated to identifying the domain of high-value likelihood
functions, while the local-refining procedure is specifically designed to
enhance the surrogate likelihood within this localized domain. Additionally, we
present two simulation-based approximations for the transition density, aiming
to efficiently or accurately approximate the likelihood function. Numerical
examples illustrate the efficacy of our proposed methodology in achieving
posterior parameter estimation
rPPG-MAE: Self-supervised Pre-training with Masked Autoencoders for Remote Physiological Measurement
Remote photoplethysmography (rPPG) is an important technique for perceiving
human vital signs, which has received extensive attention. For a long time,
researchers have focused on supervised methods that rely on large amounts of
labeled data. These methods are limited by the requirement for large amounts of
data and the difficulty of acquiring ground truth physiological signals. To
address these issues, several self-supervised methods based on contrastive
learning have been proposed. However, they focus on the contrastive learning
between samples, which neglect the inherent self-similar prior in physiological
signals and seem to have a limited ability to cope with noisy. In this paper, a
linear self-supervised reconstruction task was designed for extracting the
inherent self-similar prior in physiological signals. Besides, a specific
noise-insensitive strategy was explored for reducing the interference of motion
and illumination. The proposed framework in this paper, namely rPPG-MAE,
demonstrates excellent performance even on the challenging VIPL-HR dataset. We
also evaluate the proposed method on two public datasets, namely PURE and
UBFC-rPPG. The results show that our method not only outperforms existing
self-supervised methods but also exceeds the state-of-the-art (SOTA) supervised
methods. One important observation is that the quality of the dataset seems
more important than the size in self-supervised pre-training of rPPG. The
source code is released at https://github.com/linuxsino/rPPG-MAE
Multi-scale Promoted Self-adjusting Correlation Learning for Facial Action Unit Detection
Facial Action Unit (AU) detection is a crucial task in affective computing
and social robotics as it helps to identify emotions expressed through facial
expressions. Anatomically, there are innumerable correlations between AUs,
which contain rich information and are vital for AU detection. Previous methods
used fixed AU correlations based on expert experience or statistical rules on
specific benchmarks, but it is challenging to comprehensively reflect complex
correlations between AUs via hand-crafted settings. There are alternative
methods that employ a fully connected graph to learn these dependencies
exhaustively. However, these approaches can result in a computational explosion
and high dependency with a large dataset. To address these challenges, this
paper proposes a novel self-adjusting AU-correlation learning (SACL) method
with less computation for AU detection. This method adaptively learns and
updates AU correlation graphs by efficiently leveraging the characteristics of
different levels of AU motion and emotion representation information extracted
in different stages of the network. Moreover, this paper explores the role of
multi-scale learning in correlation information extraction, and design a simple
yet effective multi-scale feature learning (MSFL) method to promote better
performance in AU detection. By integrating AU correlation information with
multi-scale features, the proposed method obtains a more robust feature
representation for the final AU detection. Extensive experiments show that the
proposed method outperforms the state-of-the-art methods on widely used AU
detection benchmark datasets, with only 28.7\% and 12.0\% of the parameters and
FLOPs of the best method, respectively. The code for this method is available
at \url{https://github.com/linuxsino/Self-adjusting-AU}.Comment: 13pages, 7 figure
Finite element analysis of rapid canine retraction through reducing resistance and distraction
Objective: The aims of this study were to compare different surgical approaches to rapid canine retraction by designing and selecting the most effective method of reducing resistance by a three-dimensional finite element analysis. Material and Methods: Three-dimensional finite element models of different approaches to rapid canine retraction by reducing resistance and distraction were established, including maxillary teeth, periodontal ligament, and alveolar. The models were designed to dissect the periodontal ligament, root, and alveolar separately. A 1.5 N force vector was loaded bilaterally to the center of the crown between first molar and canine, to retract the canine distally. The value of total deformation was used to assess the initial displacement of the canine and molar at the beginning of force loading. Stress intensity and force distribution were analyzed and evaluated by Ansys 13.0 through comparison of equivalent (von Mises) stress and maximum shear stress. Results: The maximum value of total deformation with the three kinds of models occurred in the distal part of the canine crown and gradually reduced from the crown to the apex of the canine; compared with the canines in model 3 and model 1, the canine in model 2 had the maximum value of displacement, up to 1.9812 mm. The lowest equivalent (von Mises) stress and the lowest maximum shear stress were concentrated mainly on the distal side of the canine root in model 2. The distribution of equivalent (von Mises) stress and maximum shear stress on the PDL of the canine in the three models was highly concentrated on the distal edge of the canine cervix. . Conclusions: Removal of the bone in the pathway of canine retraction results in low stress intensity for canine movement. Periodontal distraction aided by surgical undermining of the interseptal bone would reduce resistance and effectively accelerate the speed of canine retraction
Spatio-temporal reconstruction for 3D motion recovery
—This paper addresses the challenge of 3D motion
recovery by exploiting the spatio-temporal correlations of corrupted 3D skeleton sequences. We propose a new 3D motion recovery method using spatio-temporal reconstruction, which uses
joint low-rank and sparse priors to exploit temporal correlation
and an isometric constraint for spatial correlation. The proposed
model is formulated as a constrained optimization problem,
which is efficiently solved by the augmented Lagrangian method
with a Gauss-Newton solver for the subproblem of isometric
optimization. Experimental results on the CMU motion capture
dataset, Edinburgh dataset and two Kinect datasets demonstrate
that the proposed approach achieves better motion recovery
than state-of-the-art methods. The proposed method is applicable
to Kinect-like skeleton tracking devices and pose estimation
methods that cannot provide accurate estimation of complex
motions, especially in the presence of occlusion
Loss of Scribble confers cisplatin resistance during NSCLC chemotherapy via Nox2/ROS and Nrf2/PD-L1 signaling
Background: Cisplatin resistance remains a major clinical obstacle to the successful treatment of non-small cell lung cancer (NSCLC). Scribble contributes to ROS-induced inflammation and cisplatin-elevated toxic reactive oxygen species (ROS) promotes cell death. However, it is unknown whether and how Scribble is involved in the cisplatin-related cell death and the underlying mechanism of Scribble in response to chemotherapies and in the process of oxidative stress in NSCLC. Methods: We used two independent cohorts of NSCLC samples derived from patients treated with platinumcontaining chemotherapy and xenograft modeling in vivo. We analyzed the correlation between Scribble and Nox2 or Nrf2/PD-L1 both in vivo and in vitro, and explored the role of Scribble in cisplatin-induced ROS and apoptosis. Findings: Clinical analysis revealed that Scribble expression positively correlatedwith clinical outcomes and chemotherapeutic sensitivity in NSCLC patients. Scribble protected Nox2 protein from proteasomal degradation. Scribble knockdown induced cisplatin resistance by blocking Nox2/ROS and apoptosis in LRR domaindependent manner. In addition, low levels of Scribble correlated with high levels of PD-L1 via activation of Nrf2 transcription in vivo and in vitro. Interpretations: Our study revealed that polarity protein Scribble increased cisplatin-induced ROS generation and is beneficial to chemotherapeutic outcomes in NSCLC. Although Scribble deficiency tends to lead to cisplatin resistance by Nox2/ROS and Nrf2
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