Depth Level Research Articles

Content-illumination coupling guided low-light image enhancement network

Current low-light enhancement algorithms fail to suppress noise when enhancing brightness, and may introduces structural distortion and color distortion caused by halos or artifacts. This paper proposes a content-illumination coupling guided low-light image enhancement network (CICGNet), it develops a truss topology based on Retinex as backbone to decompose low-light image component in an end-to-end way. The preservation of content features and the enhancement of illumination features are carried out along with depth and width direction of the truss topology. Each submodule uses the same resolution input and output to avoid the introduction of noise. Illumination component prevents misestimation of global and local illumination by using pre- and post-activation features at different depth levels, this way could avoid possible halos and artifacts. The network progressively enhances the illumination component and maintains the content component stage-by-stage. The proposed algorithm demonstrates better performance compared with advanced attention-based low-light enhancement algorithms and state-of-the-art image restoration algorithms. We also perform extensive ablation studies and demonstrate the impact of low-light enhancement algorithm on the downstream task of computer vision. Code is available at: https://github.com/Ruini94/CICGNet.

Vitamin B5 supplementation enhances intestinal development and alters microbes in weaned piglets

This study explored the effects of different vitamin B5 (VB5) levels on intestinal growth and function of weaned piglets. Twenty-one piglets (7.20 ± 1.11 kg) were included in a 28-day feeding trial with three treatments, including 0 mg/kg (L-VB5), 10 mg/kg (Control) and 50 mg/kg (H-VB5) of VB5 supplement. The results showed that: Large intestine weight/body weight was the highest in H-VB5 group, Control and H-VB5 groups had significantly higher villus height and villus height/crypt depth than the L-VB5 in the ileum (p < .05). Goblet cells (ileal crypt) and endocrine cells (ileal villus) significantly increased in Control and H-VB5 (p < .05). The H-VB5 group exhibited significantly higher levels of ki67 and crypt depth in the cecum and colon, colonic goblet cells and endocrine cells were both rising considerably (p < .05). Isobutyric acid and isovaleric acid were significantly reduced in the H-VB5 group (p < .05), and there was a decreasing trend in butyric acid (p = .073). At the genus level, the relative abundance of harmful bacteria such as Clostridium_Sensu_Structo_1 Strecto_1, Terrisporbacter and Streptococcus decreased significantly and the relative abundance of beneficial bacteria Turicibacter increased significantly in H-VB5 group (p < .05). Overall, the addition of 50 mg/kg VB5 primarily enhanced the morphological structure, cell proliferation and differentiation of the ileum, cecum and colon. It also had a significant impact on the gut microbiota and short-chain fatty acids.

Clinical and radiographic outcomes around 4 mandibular implant-retained overdentures in individuals with type 2 diabetes: A long-term retrospective study

ObjectivesTo report the implant survival rates, clinical, and radiographic status after a period of more than 5 years in the function of 4 inter-foraminal implants retaining mandibular overdentures (OVDs) in individuals with T2DM. Methods78 completely edentulous participants with type 2 diabetic mellitus (T2DM) who had worn mandibular OVDs retained by 4 inter-foraminal implants for long-term functional life were selected for this study. The participants were divided into 2 groups according to glycosylated haemoglobin A1c (HbA1c) levels before implant placement: group I with an HbA1c value > 6.5 % (inadequately controlled T2DM), and group II with an HbA1c value ≤6.5 % (well-controlled T2DM). The inadequately controlled T2DM was further subdivided into 2 groups: Group IA with an HbA1c value > 6.5 % and ≤8 % (moderately controlled), and Group IB has an HbA1c value > 8 % (poorly controlled). Implant survival rate, plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone level (CBL) around implants were measured. ResultsAmong 312 implants, 6 failed, 4 in well-controlled diabetics, and 2 in inadequately controlled diabetics. The overall survival rate was 98.07 %. The mean PI in group Ι was 36.4 (group IA =37.76, group IB = 34.27), and in group ΙΙ it was 19. The mean BOP in group Ι was 45.5 (group IA =47.84, group IB = 41.76), and in group ΙΙ it was 22. The mean PD in group Ι was 4.1 (group IA =4.3, group IB = 3.85) and in group ΙΙ was 2.2. The mean radiographic CBL in group Ι was 3.4 (group IA =3.7, group IB = 2.9), and in group ΙΙ was 1.5. Group IA exhibited a significantly greater level of PI, BOP, PD, and CBL compared to group IB and group IΙ (P1=0.017, P2=0.001). ConclusionsIndividuals with T2DM can benefit from 4 inter-foraminal implants retained mandibular OVDs, and their inability to maintain proper glucose control may not exclude implant success. Clinical significanceThis study is a significant step toward improving knowledge of options available for treatment and anticipated outcomes for T2DM completely edentulous populations undergoing implant therapy.

Exploring the Heterogeneous Impact of Trade Agreements on Trade: Depth Matters

Abstract One of the most relevant features in the context of international trade in recent decades is the increase in the depth of trade agreements. The aim of this article is to explore the heterogeneous effect of preferential trade agreements (PTAs) on bilateral trade flows including their depth in addition to other agreement characteristics such as the geographical scope of the member countries, their degree of development, or their nature. To measure depth, we follow the most recent works that propose indirect instead of direct measures. Once we control for depth, our results reveal that (i) the positive effect of regional PTAs is notably larger for deep agreements whereas the shallow interregional agreements do not seem to increase bilateral trade flows; (ii) North–North PTAs only boost trade when they exhibit a high depth level; and (iii) the depth is not a relevant factor for plurilateral agreements and those that consist of the adhesion of a country to an existent PTA.

Effects of Rinsing with Povidone-Iodine during Step II Periodontal Therapy: A Systematic Review and Meta-Analysis.

Background and Objectives: Antiseptics have been suggested to enhance the outcomes of non-surgical periodontal treatment (NSPT). Among these, povidone-iodine (PVP-iodine) was reported to significantly reduce periodontal pocket depths (PPDs). The aim of this study was to systematically re-assess the existing literature regarding the potential benefit of using PVP-iodine in step II periodontal therapy. Material and Methods: The scientific literature was systematically searched across electronic libraries for randomized controlled trials employing PVP-iodine during NSPT through to September 2023, using search items related to PVP-iodine and periodontitis. The selection process was performed by two independent reviewers. The primary outcomes were reductions in periodontal probing depth (PPD) and clinical attachment level (CAL). When reasonable, a meta-analysis of the included studies was performed. Results: Initially, 799 records were identified. After abstract and title screening and fulltext revision, 15 RCTs were included. The data from eight studies were merged in meta-analyses. The use of PVP-iodine had no significant effect on PPD reduction at 6 months (means [standard deviation]: -0.12 mm [-0.33; 0.09]) but it did at 12 months (-0.29 mm [-0.56; -0.02]). CAL was significantly better at 6 (-0.42 mm [-0.64; -0.20]) and 12 months (-0.39 mm [-0.66; -0.11]). Conclusions: PVP-iodine rinsing during NSPT may slightly improve patients' PPD and CAL.

Comparative Evaluation of Periodontal Ligament-associated Protein-1/Asporin Levels in Periodontal Tissue in Health and Disease.

Periodontal ligament-associated protein-1 (PLAP-1)/asporin is an extracellular matrix protein that plays a protective role in the pathogenesis of periodontitis. There is a paucity of information about the association between PLAP-1/asporin and periodontitis in human PDL. Thus, in this study, PLAP-1/asporin levels between participants with healthy periodontium and chronic periodontitis were compared and correlated with periodontal parameters. Fifty participants were recruited and divided into 25 in each group: Group 1 (control) and Group 2 (test). Probing pocket depth (PPD) and clinical attachment level (CAL) were recorded. Periodontal ligament (PDL) samples were collected from extracted teeth for estimating PLAP-1/asporin levels using the Human Asporin Enzyme-Linked Immunoassay Kit. A statistically significant difference (P = 0.001) in the PLAP-1/asporin levels was observed between Group 1 and Group 2. A weak negative correlation was observed between PLAP-1/asporin levels and periodontal parameters (PPD and CAL) in both groups. In this study, higher PLAP-1/asporin levels in participants with healthy periodontium highlight the protective role of PLAP-1/asporin in maintaining periodontal homeostasis.

Early Devonian Post‐collisional Granitic Magmatism in the North Qilian Orogenic Belt, Western China: Insights into Lithospheric Delamination and Orogenic Collapse

AbstractPost‐collisional magmatism contains important clues for understanding the reworking and growth of continental crust, as well as lithospheric delamination and orogenic collapse. Early Devonian magmatism has been identified in the North Qilian Orogenic Belt (NQOB). This paper reports an integrated study of petrology, whole‐rock geochemistry, Sm‐Nd isotope and zircon U‐Pb dating, as well as Lu‐Hf isotopic data, for two Early Devonian intrusive plutons. The Yongchang and Chijin granites yield zircon U‐Pb ages of 394–407 Ma and 414 Ma, respectively. Both of them are characterized by weakly peraluminous to metaluminous without typical aluminium‐rich minerals, LREE‐enriched patterns with negative Eu anomalies and a negative correlation between P2O5 and SiO2 contents, consistent with geochemical features of I‐type granitoids. Zircons from the studied granites display negative to weak positive εHf(t) values (–5.7 to 2.1), which agree well with those of negative εNd(t) values (−6.4 to −2.9) for the whole‐rock samples, indicating that they were derived from the partial melting of Mesoproterozoic crust. Furthermore, low Sr/Y ratios (1.13–21.28) and high zircon saturation temperatures (745°C to 839°C, with the majority being &gt;800°C) demonstrated a relatively shallow depth level below the garnet stability field and an additional heat source. Taken together, the Early Devonian granitic magmatism could have been produced by the partial melting of ancient crustal materials heated by mantle‐derived magmas at high‐temperature and low‐pressure conditions during post‐collisional extensional collapse. The data obtained in this study, when viewed in conjunction with previous studies, provides more information about the tectonic processes that followed the closure of the North Qilian Ocean. The tectonic transition from continental collision to post‐collisional delamination could be constrained to ∼430 Ma, which is provided by the sudden decrease of Sr/Y and La/Yb ratios and an increase in zircon εHf(t) values for granitoids. A two‐stage tectonic evolution model from continental collision to post‐collisional extensional collapse for the NQOB includes (a) continental collision and crustal thickening during ca. 455–430 Ma, characterized by granulite‐facies metamorphism and widespread low‐Mg adakitic magmatism; (b) post‐collisional delamination of thickened continental crust and extensional collapse of orogen during ca. 430–390 Ma, provided by coeval high‐Mg adakitic magmatism, A‐type granites and I‐type granitoids with low Sr‐Y ratios.

The Upwelling Source Depth Distribution and Its Response to Wind Stress and Stratification

Abstract Coastal upwelling, driven by alongshore winds and characterized by cold sea surface temperatures and high upper-ocean nutrient content, is an important physical process sustaining some of the oceans’ most productive ecosystems. To fully understand the ocean properties in eastern boundary upwelling systems, it is important to consider the depth of the source waters being upwelled, as it affects both the SST and the transport of nutrients toward the surface. Here, we construct an upwelling source depth distribution for parcels at the surface in the upwelling zone. We do so using passive tracers forced at the domain boundary for every model depth level to quantify their contributions to the upwelled waters. We test the dependence of this distribution on the strength of the wind stress and stratification using high-resolution regional ocean simulations of an idealized coastal upwelling system. We also present an efficient method for estimating the mean upwelling source depth. Furthermore, we show that the standard deviation of the upwelling source depth distribution increases with increasing wind stress and decreases with increasing stratification. These results can be applied to better understand and predict how coastal upwelling sites and their surface properties have and will change in past and future climates.

Effect of Financial Depth on Output and Economic Growth

A lot of theoretical insights have been provided on the relationship between the financial and real sectors of the economy. The emerging theoretical postulations, which are devoid of consensus, have since been the subject of empirical investigations in respect of which, again, there is no consensus, not to talk of unanimity. Thus, this state of lack of consensus in the findings of the existing empirical studies calls for further studies that are aimed at resolving the contradictions. This informs the objective of the study, which is to examine the effect of financial depth on output and economic growth across African countries spanning from 1980 to 2019. The theoretical background rests on neo-classical theory and the supply-leading hypothesis. The study employed the dynamic fixed effect (DFE) estimation technique. The result reported that the three alternative proxies for the level of financial depth have positive effects on both overall economic growth and sectoral output growth. Also, each of the seven conditioning variables has the expected effects on economic growth. Based on the findings, the study therefore recommends that policymakers take measures aimed at deepening the level of the different forms of finance in order to promote economic growth.

Analyzing the Impact of Storm ‘Daniel’ and Subsequent Flooding on Thessaly’s Soil Chemistry through Causal Inference

Storm ‘Daniel’ caused the most severe flood phenomenon that Greece has ever experienced, with thousands of hectares of farmland submerged for days. This led to sediment deposition in the inundated areas, which significantly altered the chemical properties of the soil, as revealed by extensive soil sampling and laboratory analysis. The causal relationships between the soil chemical properties and sediment deposition were extracted using the DirectLiNGAM algorithm. The results of the causality analysis showed that the sediment deposition affected the CaCO3 concentration in the soil. Also, causal relationships were identified between CaCO3 and the available phosphorus (P-Olsen), as well as those between the sediment deposit depth and available manganese. The quantified relationships between the soil variables were then used to generate data using a Multiple Linear Perceptron (MLP) regressor for various levels of deposit depth (0, 5, 10, 15, 20, 25, and 30 cm). Then, linear regression equations were fitted across the different levels of deposit depth to determine the effect of the deposit depth on CaCO3, P, and Mn. The results revealed quadratic equations for CaCO3, P, and Mn as follows: 0.001XCaCO32 + 0.08XCaCO3 + 6.42, 0.004XP2 − 0.26XP + 12.29, and 0.003XMn2 − 0.08XMn + 22.47, respectively. The statistical analysis indicated that corn growing in soils with a sediment over 10 cm requires a 31.8% increase in the P rate to prevent yield decline. Additional notifications regarding cropping strategies in the near future are also discussed.

Flood Impacts on Agriculture under Climate Change: The case of the Awanui Catchment, New Zealand

We assess the economic and environmental impacts on agriculture of flooding under projected climate change, including land-use change as an adaption response to floods. Our case study area is the Awanui catchment located in the far north of New Zealand, where flooding is a significant hazard. The study uses an integrated approach and combines spatial information on agricultural exposure and damage from flooding, economic land-use modelling, and valuation approaches. We analyse direct tangible and direct intangible flood impacts under various extents, frequencies, and water depth levels. Our results show areas with flood exposure and damage costs increase with projected climate change. As an adaptation measure to reduce flood damage costs, pastoral farms convert to other land uses, mainly to unfarmed land. Flooding reduces the net revenue for the catchment, while it can result in some reduction of environmental pollution. When the probability of all possible flood events are considered, the value of the changes in greenhouse gas emissions are equivalent to approximately 18% of the change in total net revenue, while the value of changes in other environmental outputs is equivalent to less than 1% of the change in total net revenue. Based on this study, the assessment of various flood impacts and adaptation responses to them can help to develop resilience strategies for the agricultural sector to future climate-induced flooding.

Bridge pier under coupled earthquake and wave - Current actions: Numerical model establishing, optimization and structural response analysis

Bridges located in earthquake-prone areas may be subjected to earthquake, wave and current actions simultaneously. Current investigations on bridge piers under these complex loading conditions were generally performed through underwater shaking table (UST) tests, which required advanced test setups and great expenses. With the aim of eliminating these limits and developing a comprehensive understanding of the performance of deep-water bridge piers under coupled earthquake and wave-current actions, the present study carried out systematic numerical investigations. Wave generation and propagation were first simulated, for which thorough sensitivity analysis was conducted to obtain the optimal parameters, including mesh size, time step intervals, damping zone length and damping coefficients. Numerical models which are able to simulate nonlinear wave-current interactions were then established and validated. Following this, structural responses of bridge piers under wave, wave-current and coupled earthquake and wave-current actions were numerically simulated and validated by test results. Finally, parametric analysis was conducted on a pile of a practical deep-water bridge in China using the validated model with consideration of various water depth levels, diverse wave heights, different current velocities, varied earthquakes and different peak ground accelerations to reveal the influence of different excitation parameters on structural responses.

Entire papilla preservation technique for treatment of periodontal intrabony defects: a series of cases.

Periodontitis is characterized by bone resorption. Vertical bone loss results in an intraosseous defect. Multiple surgical approaches for treating intrabony defects have shown different grades of effectiveness. Recently, the entire papilla preservation technique has been proposed, improving clinical parameters, such as pocket depth and clinical attachment level. This series of cases aimed to describe the use of the entire papilla preservation surgical technique without using biomaterials to regenerate periodontal intrabony defects. The influence on the clinical periodontal parameters and radiographic parameters was measured through CBCT, the latter not described until now, and analyzed the possible postoperative complications. A total of six intrabony periodontal defects associated with at least one periodontal pocket with probing depths equal to or greater than 6 mm were treated with the entire papilla preservation technique. The clinical and radiographic parameters were evaluated at the beginning and 6 months after surgery. The mean probing pocket depth reduction was 4.00 ± 0.63 mm, the mean clinical attachment level gain was 3.67 ± 1.03 mm, and the mean radiographic intrabony filling was 2.41 ± 2.03 mm. Early healing was uneventful; the mean visual analog scale at 7 days was 0. This minimally invasive technique results in an improvement in clinical and radiographic parameters, the latter showing a filling of the bone defect observed during the 6-month evaluation after surgical treatment. These results confirm the importance of clot and flap stability in regenerating intraosseous defects.

Trace and rare earth elements in phytoplankton from the Tyrrhenian Sea (Italy).

Plankton plays a very crucial role in bioaccumulation and transfer of metals in the marine food web and represents a suitable bioindicator of the occurrence of trace and rare earth elements in the ecosystem. Trace elements and REEs were analyzed by ICP-MS in phytoplankton samples from the northwestern Mediterranean Sea. Metal concentrations in phytoplankton were found strongly influenced by seasons and depth of collection (- 30m, - 50m). Principal component analysis (PCA) has shown that Al, As, Cr, Cu, Ga, and Sn concentrations were related to summer and autumn in samples collected at 30m depth, while Fe, Mn, Ni, V, and Zn levels related strongly with summer and spring at 50m depth. Fe, Al, and Zn were the most represented elements in all samples (mean values respectively in the ranges 4.2-8.2, 9.6-13, and 1.0-4.4mgkg-1) according to their widespread presence in the environment and in the earth crust. Principal component analysis (PCA) performed on REEs showed that mostly all lanthanides' concentrations strongly correlate with summer and autumn seasons (- 30m depth); the highest ∑REE concentration (75µgkg-1) was found in winter. Phytoplankton REE normalized profile was comparable to those of other marine biota collected in the same area according to the suitability of lanthanides as geological tracers.

A Hybrid Global-Local Perception Network for Lane Detection

Lane detection is a critical task in autonomous driving, which requires accurately predicting the complex topology of lanes in various scenarios. While previous methods of lane detection have shown success, challenges still exist, especially in scenarios where lane markings are absent. In this paper, we analyze the role of global and local features in accurately detecting lanes and propose a Hybrid Global-Local Perception Network (HGLNet) to leverage them. Global and local features play distinct roles in lane detection by respectively aiding in the detection of lane instances and the localization of corresponding lanes. HGLNet extracts global semantic context by utilizing a global extraction head that aggregates information about adaptive sampling points around lanes, achieving an optimal trade-off between performance and efficiency. Moreover, we introduce a Multi-hierarchy feature aggregator (MFA) to capture feature hierarchies in both regional and local ranges, elevating the representation of local features. The proposed Hybrid architecture can simultaneously focus on global and local features at different depth levels and efficiently integrate them to sense the global presence of lanes and accurately regress their locations. Experimental results demonstrate that our proposed method improves detection accuracy in various challenging scenarios, outperforming the state-of-the-art lane detection methods.

Rectangle Search: An Anytime Beam Search

Anytime heuristic search algorithms try to find a (potentially suboptimal) solution as quickly as possible and then work to find better and better solutions until an optimal solution is obtained or time is exhausted. The most widely-known anytime search algorithms are based on best-first search. In this paper, we propose a new algorithm, rectangle search, that is instead based on beam search, a variant of breadth-first search. It repeatedly explores alternatives at all depth levels and is thus best-suited to problems featuring deep local minima. Experiments using a variety of popular search benchmarks suggest that rectangle search is competitive with fixed-width beam search and often performs better than the previous best anytime search algorithms.

Comparison of environmental DNA and underwater visual count surveys for detecting juvenile Coho Salmon in small rivers

AbstractObjectiveThis study compares the probability of detecting juvenile Coho Salmon Oncorhynchus kisutch using both environmental DNA (eDNA) techniques and underwater visual count (UVC) surveys in northern California rivers. Here, UVC surveys commonly have detection probabilities (p) surpassing 0.90, providing an ideal setting to examine the performance of newer eDNA methods. We also evaluate the potential for using eDNA concentrations to predict the count of Coho Salmon within pool habitats.MethodsWe conducted paired eDNA and UVC surveys in 96 pools across 25 stream reaches within the Smith River basin, California. Method‐specific p and the effect of environmental covariates were estimated using multiscale occupancy modeling. We used generalized linear models to evaluate the relationship of fish counts to eDNA concentrations and habitat covariates.ResultThe eDNA and UVC methods showed a high degree of agreement in detecting the presence of Coho Salmon within a pool (93% agreement) and survey reach (80% agreement). Detection probabilities for eDNA (peDNA) and for UVC (pUVC) were similar and high at median levels of pool residual depth and contributing basin area (peDNA = 91%, pUVC = 89%). Contributing basin area (a proxy for discharge) had a strong, negative effect that was more pronounced for peDNA than for pUVC (e.g., in the largest basins, peDNA = 34% whereas pUVC = 77%). We did not find eDNA concentrations to be a good predictor of Coho Salmon counts in small pools.ConclusionThis study demonstrates that eDNA methods yielded nearly identical results to UVC surveys in catchments &lt;36 km2 and can provide a highly effective approach for determining the distribution of Coho Salmon. However, additional investigation is required before eDNA could be used to estimate relative abundance in small pools.

Two-Stage Model of Devonian Basic Magmatism in the Vilyui Paleorift (Siberian Platform)

Abstract —We report study results of basic intrusive bodies in the middle Paleozoic Vilyui paleorift (eastern Siberian Platform). Geochemical data for basic sills penetrated by boreholes in the rift’s dike swarms are presented, as well as our data on the time of formation of sills and dikes. We also studied mineral-hosted melt inclusions from a dolerite dike of the Vilyui–Markha dike swarm on the northwestern flank of the Vilyui paleorift. Data on the compositions of homogenous glasses of mineral-hosted melt inclusions yielded the P–T parameters of mantle sources of basic melts responsible for the formation of the Vilyui paleorift gabbro-dolerites. Two depth levels of basic melt generation have been established: 95–65 km at 1480–1400 °C and 55–45 km at 1360–1320 °C. Crystallization of the melts occurred at a shallow depth of 12–4 km with a decrease in temperature from 1185 to 1125 ºС. This occurrence of basic melt sources at two different depths, as well as the heterogeneity of the chemical composition of melt inclusions and their host minerals explains the presence of two pulses of Devonian basic magmatism. Our new numerical thermomechanical model of magma rise during melting of the lithospheric mantle above a mantle plume supports the existence of two chambers at the spinel–garnet peridotite boundary and under the base of the crust, as well as the two-stage nature of Devonian magmatism.

Development of a High-throughput Sequencing Platform for Detection of Viral Encephalitis Pathogens Based on Amplicon Sequencing*

ObjectiveViral encephalitis is an infectious disease severely affecting human health. It is caused by a wide variety of viral pathogens, including herpes viruses, flaviviruses, enteroviruses, and other viruses. The laboratory diagnosis of viral encephalitis is a worldwide challenge. Recently, high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections. Thus, In this study, we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing. MethodsWe designed nine pairs of specific polymerase chain reaction (PCR) primers for the 12 viruses by reviewing the relevant literature. The detection ability of the primers was verified by software simulation and the detection of known positive samples. Amplicon sequencing was used to validate the samples, and consistency was compared with Sanger sequencing. ResultsThe results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×, and the sequence lengths were consistent with the sizes of the predicted amplicons. The sequences were verified using the National Center for Biotechnology Information BLAST, and all results were consistent with the results of Sanger sequencing. ConclusionAmplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis. It is also a useful tool for the high-volume screening of clinical samples.

Adaptive quadtree splitting parallelization (AQSP) algorithm for the VVC standard

The Versatile Video Coding (VVC) standard, also known as H.266, was released in 2020 as the natural successor to the High Efficiency Video Coding (HEVC) standard. Among its innovative coding tools, VVC extended the concept of quadtree (QT) splitting to the multi-type tree (MTT) structure, introducing binary and ternary partitions to enhance HEVC’s coding efficiency. While this brought significant compression improvements, it also resulted in a substantial increase in encoding time, primarily due to VVC’s larger Coding Tree Unit (CTU) size of 128×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document}128 pixels. To mitigate this, this work introduces a flexible parallel approach for the QT traversal and splitting scheme of the VVC encoder, called adaptive quadtree splitting parallelization (AQSP) algorithm. This approach is based on the distribution of coding units (CUs) among different threads using the current depth level of the QT as a basis to minimize the number of broken dependencies. In this way, the algorithm achieves a good trade-off between time savings and coding efficiency. Experimental results show that, when compared with the original VVC encoder, AQSP achieves an acceleration factor of 2.04×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document} with 4 threads at the expense of a low impact in terms of BD rate. These outcomes position AQSP competitively in comparison with other state-of-the-art approaches.