63 research outputs found
Complexity of Saliency-Cognizant Error Concealment Based on the Itti-Koch-Niebur Saliency Model
LCCM-VC: Learned Conditional Coding Modes for Video Compression
End-to-end learning-based video compression has made steady progress over the
last several years. However, unlike learning-based image coding, which has
already surpassed its handcrafted counterparts, learning-based video coding
still has some ways to go. In this paper we present learned conditional coding
modes for video coding (LCCM-VC), a video coding model that achieves
state-of-the-art results among learning-based video coding methods. Our model
utilizes conditional coding engines from the recent conditional augmented
normalizing flows (CANF) pipeline, and introduces additional coding modes to
improve compression performance. The compression efficiency is especially good
in the high-quality/high-bitrate range, which is important for broadcast and
video-on-demand streaming applications. The implementation of LCCM-VC is
available at https://github.com/hadihdz/lccm_vcComment: 5 pages, 3 figures, IEEE ICASSP 202
Learned Scalable Video Coding For Humans and Machines
Video coding has traditionally been developed to support services such as
video streaming, videoconferencing, digital TV, and so on. The main intent was
to enable human viewing of the encoded content. However, with the advances in
deep neural networks (DNNs), encoded video is increasingly being used for
automatic video analytics performed by machines. In applications such as
automatic traffic monitoring, analytics such as vehicle detection, tracking and
counting, would run continuously, while human viewing could be required
occasionally to review potential incidents. To support such applications, a new
paradigm for video coding is needed that will facilitate efficient
representation and compression of video for both machine and human use in a
scalable manner. In this manuscript, we introduce the first end-to-end
learnable video codec that supports a machine vision task in its base layer,
while its enhancement layer supports input reconstruction for human viewing.
The proposed system is constructed based on the concept of conditional coding
to achieve better compression gains. Comprehensive experimental evaluations
conducted on four standard video datasets demonstrate that our framework
outperforms both state-of-the-art learned and conventional video codecs in its
base layer, while maintaining comparable performance on the human vision task
in its enhancement layer. We will provide the implementation of the proposed
system at www.github.com upon completion of the review process.Comment: 14 pages, 16 figure
Unsupervised Video Summarization via Reinforcement Learning and a Trained Evaluator
This paper presents a novel approach for unsupervised video summarization
using reinforcement learning. It aims to address the existing limitations of
current unsupervised methods, including unstable training of adversarial
generator-discriminator architectures and reliance on hand-crafted reward
functions for quality evaluation. The proposed method is based on the concept
that a concise and informative summary should result in a reconstructed video
that closely resembles the original. The summarizer model assigns an importance
score to each frame and generates a video summary. In the proposed scheme,
reinforcement learning, coupled with a unique reward generation pipeline, is
employed to train the summarizer model. The reward generation pipeline trains
the summarizer to create summaries that lead to improved reconstructions. It
comprises a generator model capable of reconstructing masked frames from a
partially masked video, along with a reward mechanism that compares the
reconstructed video from the summary against the original. The video generator
is trained in a self-supervised manner to reconstruct randomly masked frames,
enhancing its ability to generate accurate summaries. This training pipeline
results in a summarizer model that better mimics human-generated video
summaries compared to methods relying on hand-crafted rewards. The training
process consists of two stable and isolated training steps, unlike adversarial
architectures. Experimental results demonstrate promising performance, with
F-scores of 62.3 and 54.5 on TVSum and SumMe datasets, respectively.
Additionally, the inference stage is 300 times faster than our previously
reported state-of-the-art method
Synthesis and Effects of 4,5-Diaryl-2-(2-alkylthio-5-imidazolyl) Imidazoles as Selective Cyclooxygenase Inhibitors
Objective(s)In recent years highly selective COX-2inhibitors were withdrawn from the market because of an increased risk of cardiovascular complications. In this study we were looking for potent compounds with moderate selectivity for cox-2. So, four analogues of 4, 5-diaryl-2-(2-alkylthio-5-imidazolyl) imidazole derivatives were synthesized and their anti-inflammatory and anti-nociceptive activities were evaluated on male BALB/c mice (25-30 g). Molecular modeling and in vitro COX-1 and COX-2 isozyme inhibition studies were also performed. Materials and Methods2-(2-Alkylthio-5-imidazolyl)-4,5-diphenylimidazole compounds were obtained by the reaction of benzyl with 2-alkylthio-1-benzylimidazole-5-carbaldehyde, in the presence of ammonium acetate. Spectroscopic data and elemental analysis of compounds were obtained and their structures elucidated. Anti-nociception effects were examined using writhing test in mice. The effect of the analogues (7.5, 30, 52.5 and 75 mg/kg) against acute inflammation were studied using xylene-induced ear edema test in mice. Celecoxib (75 mg/kg) was used as positive control.ResultsAll four analogues exhibited anti-nociceptive activity against acetic acid induced writhing, but did not show significant analgesic effect (P< 0.05) compared with celecoxib. It was shown that analogues injected 30 min before xylene application reduced the weight of edematic ears. All analogues were found to have less selectivity for COX-2 in comparison to celecoxib. ConclusionInjected doses of synthesised analogues possesses favorite anti-nociceptive effect and also has anti-inflammatory effects, but comparing with celecoxib this effect is not significantly different. On the other hand selectivity index for analogues is less than celecoxib and so we expect less cardiovascular side effects for these compounds
Learned Multimodal Compression for Autonomous Driving
Autonomous driving sensors generate an enormous amount of data. In this paper, we explore learned multimodal compression for autonomous driving, specifically targeted at 3D object detection. We focus on camera and LiDAR modalities and explore several coding approaches. One approach involves joint coding of fused modalities, while others involve coding one modality first, followed by conditional coding of the other modality. We evaluate the performance of these coding schemes on the nuScenes dataset. Our experimental results indicate that joint coding of fused modalities yields better results compared to the alternatives.6 pages, 5 figures, IEEE MMSP 202
Mutual Information Analysis in Multimodal Learning Systems
In recent years, there has been a significant increase in applications of
multimodal signal processing and analysis, largely driven by the increased
availability of multimodal datasets and the rapid progress in multimodal
learning systems. Well-known examples include autonomous vehicles, audiovisual
generative systems, vision-language systems, and so on. Such systems integrate
multiple signal modalities: text, speech, images, video, LiDAR, etc., to
perform various tasks. A key issue for understanding such systems is the
relationship between various modalities and how it impacts task performance. In
this paper, we employ the concept of mutual information (MI) to gain insight
into this issue. Taking advantage of the recent progress in entropy modeling
and estimation, we develop a system called InfoMeter to estimate MI between
modalities in a multimodal learning system. We then apply InfoMeter to analyze
a multimodal 3D object detection system over a large-scale dataset for
autonomous driving. Our experiments on this system suggest that a lower MI
between modalities is beneficial for detection accuracy. This new insight may
facilitate improvements in the development of future multimodal learning
systems.Comment: 6 pages, 7 figures, IEEE MIPR 202
Research Paper: Effectiveness of Corticosteroid Therapy for Caustic Esophageal Injury
Background: Delayed caustic injury complications are common, especially in developing countries, and several treatments have been proposed to prevent the resulting esophageal strictures so far. Although inflammatory nature of caustic injury makes the anti-inflammatory agents a viable option, few studies have investigated these agents. High-dose corticosteroids therapy for reduction of stricture formation in the esophagus after the ingestion of caustic material is still a controversial topic. In this regard, this study aimed to determine the impact of high doses of methylprednisolone in preventing esophageal stricture.Methods: A total of 112 patients with grade II esophageal caustic injury, diagnosed by esophagogastroscopy within 24 hours of injury, were enrolled in our study. The treatment group (n=44) received methylprednisolone (1 g/d for 3 days), pantoprazole, ceftriaxone, and metronidazole and the control group (n=58) received the same regimen excluding methylprednisolone. Endoscopic and radiologic findings were used to compare the severity of the damage to the esophagus and stomach between the two groups.Results: After 8 months of follow-up, stricture development was observed in 3 (5.6%) patients in the treatment group and in 11 (19%) patients in the control group. The difference was statistically significant (P=0.038). The gastric outlet obstruction was observed in 4 (7.4%) patients in the treatment group and in 19 (32.7%) patients in the control group. Again, the difference was statistically significant (P<0.05). There were not any side effects due to the high doses of methylprednisolone in the study group.Conclusion: High doses of methylprednisolone can prevent the development of esophageal stricture in grade II of caustic injury
Erratum to: Surface guided 3DCRT in deep-inspiration breath‑hold for left sided breast cancer radiotherapy: implementation and first clinical experience in Iran
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