Pub Date : 2024-08-06DOI: 10.1016/j.cag.2024.104033
The display coefficients that produce the signal emitted by a light field display are usually calculated to approximate the radiance over a set of sampled rays in the light field space. However, not all information contained in the light field signal is of equal importance to an observer. We propose a retinal pre-filtering of the light field samples that takes into account the image formation process of the observer to determine display coefficients that will ultimately produce better retinal images for a range of focus distances. We demonstrate a significant increase in image definition without changing the display resolution.
{"title":"Retinal pre-filtering for light field displays","authors":"","doi":"10.1016/j.cag.2024.104033","DOIUrl":"10.1016/j.cag.2024.104033","url":null,"abstract":"<div><p>The display coefficients that produce the signal emitted by a light field display are usually calculated to approximate the radiance over a set of sampled rays in the light field space. However, not all information contained in the light field signal is of equal importance to an observer. We propose a retinal pre-filtering of the light field samples that takes into account the image formation process of the observer to determine display coefficients that will ultimately produce better retinal images for a range of focus distances. We demonstrate a significant increase in image definition without changing the display resolution.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0097849324001687/pdfft?md5=a3ada2f14da0a4ee885b3020bef4c154&pid=1-s2.0-S0097849324001687-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142040308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-06DOI: 10.1016/j.cag.2024.104025
Water and light interactions cause color shifts and blurring in underwater images, while dynamic underwater illumination further disrupts scene consistency, resulting in poor performance of optical image-based reconstruction methods underwater. Although Neural Radiance Fields (NeRF) can describe aqueous medium through volume rendering, applying it directly underwater may induce artifacts and floaters. We propose SP-SeaNeRF, which uses micro MLP to predict water column parameters and simulates the degradation process as a combination of real colors and scattered colors in underwater images, enhancing the model’s perception of scattering. We use illumination embedding vectors to learn the illumination bias within the images, in order to prevent dynamic illumination from disrupting scene consistency. We have introduced a novel sampling module, which focuses on maximum weight points, effectively improves training and inference speed. We evaluated our proposed method on SeaThru-NeRF and Neuralsea underwater datasets. The experimental results show that our method exhibits superior underwater color restoration ability, outperforming existing underwater NeRF in terms of reconstruction quality and speed.
{"title":"SP-SeaNeRF: Underwater Neural Radiance Fields with strong scattering perception","authors":"","doi":"10.1016/j.cag.2024.104025","DOIUrl":"10.1016/j.cag.2024.104025","url":null,"abstract":"<div><p>Water and light interactions cause color shifts and blurring in underwater images, while dynamic underwater illumination further disrupts scene consistency, resulting in poor performance of optical image-based reconstruction methods underwater. Although Neural Radiance Fields (NeRF) can describe aqueous medium through volume rendering, applying it directly underwater may induce artifacts and floaters. We propose SP-SeaNeRF, which uses micro MLP to predict water column parameters and simulates the degradation process as a combination of real colors and scattered colors in underwater images, enhancing the model’s perception of scattering. We use illumination embedding vectors to learn the illumination bias within the images, in order to prevent dynamic illumination from disrupting scene consistency. We have introduced a novel sampling module, which focuses on maximum weight points, effectively improves training and inference speed. We evaluated our proposed method on SeaThru-NeRF and Neuralsea underwater datasets. The experimental results show that our method exhibits superior underwater color restoration ability, outperforming existing underwater NeRF in terms of reconstruction quality and speed.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-06DOI: 10.1016/j.cag.2024.104034
Virtual Humans (VHs) emerged over 50 years ago and have since experienced notable advancements. Initially, developing and animating VHs posed significant challenges. However, modern technology, both commercially available and freely accessible, has democratized the creation and animation processes, making them more accessible to users, programmers, and designers. These advancements have led to the replication of authentic traits and behaviors of real actors in VHs, resulting in visually convincing and behaviorally lifelike characters. As a consequence, many research areas arise as functional VH technologies. This paper explored the evolution of four areas and emerging trends related to VHs while examining some of the implications and challenges posed by highly realistic characters within these domains.
{"title":"Surveying the evolution of virtual humans expressiveness toward real humans","authors":"","doi":"10.1016/j.cag.2024.104034","DOIUrl":"10.1016/j.cag.2024.104034","url":null,"abstract":"<div><p>Virtual Humans (VHs) emerged over 50 years ago and have since experienced notable advancements. Initially, developing and animating VHs posed significant challenges. However, modern technology, both commercially available and freely accessible, has democratized the creation and animation processes, making them more accessible to users, programmers, and designers. These advancements have led to the replication of authentic traits and behaviors of real actors in VHs, resulting in visually convincing and behaviorally lifelike characters. As a consequence, many research areas arise as functional VH technologies. This paper explored the evolution of four areas and emerging trends related to VHs while examining some of the implications and challenges posed by highly realistic characters within these domains.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141942921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-06DOI: 10.1016/j.cag.2024.104035
This research paper explores the impact of augmented reality (AR) tracking characteristics, specifically an AR head-worn display’s tracking registration accuracy and precision, on users’ spatial abilities and subjective perceptions of trust in and reliance on the technology. Our study aims to clarify the relationships between user performance and the different behaviors users may employ based on varying degrees of trust in and reliance on AR. Our controlled experimental setup used a 360° field-of-regard search-and-selection task and combines the immersive aspects of a CAVE-like environment with AR overlays viewed with a head-worn display.
We investigated three levels of simulated AR tracking errors in terms of both accuracy and precision (+0°, +1°, +2°). We controlled for four user task behaviors that correspond to different levels of trust in and reliance on an AR system: AR-Only (only relying on AR), AR-First (prioritizing AR over real world), Real-Only (only relying on real world), and Real-First (prioritizing real world over AR). By controlling for these behaviors, our results showed that even small amounts of AR tracking errors had noticeable effects on users’ task performance, especially if they relied completely on the AR cues (AR-Only). Our results link AR tracking characteristics with user behavior, highlighting the importance of understanding these elements to improve AR technology and user satisfaction.
本研究论文探讨了增强现实(AR)追踪特性(特别是 AR 头戴式显示器的追踪注册准确性和精确度)对用户空间能力以及对该技术信任和依赖的主观感受的影响。我们的研究旨在阐明用户表现与用户基于对 AR 不同程度的信任和依赖而采取的不同行为之间的关系。我们的受控实验设置使用了 360° 视场搜索和选择任务,并将类似 CAVE 的沉浸式环境与通过头戴式显示器查看的 AR 叠加效果相结合。我们对用户的四种任务行为进行了控制,这些行为与对 AR 系统的不同信任和依赖程度相对应:AR-Only(仅依赖 AR)、AR-First(优先考虑 AR 而非真实世界)、Real-Only(仅依赖真实世界)和 Real-First(优先考虑真实世界而非 AR)。通过对这些行为进行控制,我们的结果表明,即使是少量的 AR 跟踪错误也会对用户的任务表现产生明显影响,尤其是在用户完全依赖 AR 提示的情况下(仅依赖 AR)。我们的研究结果将 AR 跟踪特征与用户行为联系起来,强调了了解这些因素对于改进 AR 技术和提高用户满意度的重要性。
{"title":"Investigating the relationships between user behaviors and tracking factors on task performance and trust in augmented reality","authors":"","doi":"10.1016/j.cag.2024.104035","DOIUrl":"10.1016/j.cag.2024.104035","url":null,"abstract":"<div><p>This research paper explores the impact of augmented reality (AR) tracking characteristics, specifically an AR head-worn display’s tracking registration accuracy and precision, on users’ spatial abilities and subjective perceptions of trust in and reliance on the technology. Our study aims to clarify the relationships between user performance and the different behaviors users may employ based on varying degrees of trust in and reliance on AR. Our controlled experimental setup used a 360° field-of-regard search-and-selection task and combines the immersive aspects of a CAVE-like environment with AR overlays viewed with a head-worn display.</p><p>We investigated three levels of simulated AR tracking errors in terms of both accuracy and precision (+0°, +1°, +2°). We controlled for four user task behaviors that correspond to different levels of trust in and reliance on an AR system: <em>AR-Only</em> (only relying on AR), <em>AR-First</em> (prioritizing AR over real world), <em>Real-Only</em> (only relying on real world), and <em>Real-First</em> (prioritizing real world over AR). By controlling for these behaviors, our results showed that even small amounts of AR tracking errors had noticeable effects on users’ task performance, especially if they relied completely on the AR cues (AR-Only). Our results link AR tracking characteristics with user behavior, highlighting the importance of understanding these elements to improve AR technology and user satisfaction.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141964253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-05DOI: 10.1016/j.cag.2024.104023
In this paper, we investigate the suitability of different visual representations of pathological growth and shrinkage using surface models of intracranial aneurysms and liver tumors. By presenting complex medical information in a visually accessible manner, audiences can better understand and comprehend the progression of pathological structures. Previous work in medical visualization provides an extensive design space for visualizing medical image data. However, determining which visualization techniques are appropriate for a general audience has not been thoroughly investigated.
We conducted a user study (n = 40) to evaluate different visual representations in terms of their suitability for solving tasks and their aesthetics. We created surface models representing the evolution of pathological structures over multiple discrete time steps and visualized them using illumination-based and illustrative techniques. Our results indicate that users’ aesthetic preferences largely coincide with their preferred visualization technique for task-solving purposes. In general, the illumination-based technique has been preferred to the illustrative technique, but the latter offers great potential for increasing the accessibility of visualizations to users with color vision deficiencies.
{"title":"Visually communicating pathological changes: A case study on the effectiveness of phong versus outline shading","authors":"","doi":"10.1016/j.cag.2024.104023","DOIUrl":"10.1016/j.cag.2024.104023","url":null,"abstract":"<div><p>In this paper, we investigate the suitability of different visual representations of pathological growth and shrinkage using surface models of intracranial aneurysms and liver tumors. By presenting complex medical information in a visually accessible manner, audiences can better understand and comprehend the progression of pathological structures. Previous work in medical visualization provides an extensive design space for visualizing medical image data. However, determining which visualization techniques are appropriate for a general audience has not been thoroughly investigated.</p><p>We conducted a user study (n = 40) to evaluate different visual representations in terms of their suitability for solving tasks and their aesthetics. We created surface models representing the evolution of pathological structures over multiple discrete time steps and visualized them using illumination-based and illustrative techniques. Our results indicate that users’ aesthetic preferences largely coincide with their preferred visualization technique for task-solving purposes. In general, the illumination-based technique has been preferred to the illustrative technique, but the latter offers great potential for increasing the accessibility of visualizations to users with color vision deficiencies.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0097849324001584/pdfft?md5=290698cd5eeb6b5b6aca798a4452f2fb&pid=1-s2.0-S0097849324001584-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1016/j.cag.2023.12.007
{"title":"Foreword to the special section on 3D object retrieval 2023 symposium (3DOR2023)","authors":"","doi":"10.1016/j.cag.2023.12.007","DOIUrl":"10.1016/j.cag.2023.12.007","url":null,"abstract":"","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1016/j.cag.2023.08.031
{"title":"Foreword to the special section on SIBGRAPI 2023","authors":"","doi":"10.1016/j.cag.2023.08.031","DOIUrl":"10.1016/j.cag.2023.08.031","url":null,"abstract":"","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129764432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-31DOI: 10.1016/j.cag.2024.104022
Urban simulations that involve disaster prevention, urban design, and assisted navigation heavily rely on urban geometric models. While large urban areas need a lot of time to be acquired terrestrially, government organizations have already conducted massive aerial LiDAR surveys, some even at the national level. This work aims to provide a pipeline for extracting multi-scale point clouds from 2D building footprints and airborne LiDAR data, which depends on whether the points represent buildings, vegetation, or ground. We denoise the roof slopes, match the vegetation, and roughly recreate the building façades frequently hidden to aerial acquisition using a parametric representation of geometric primitives. We then carry out multiple-scale samplings of the urban geometry until a 3D urban representation can be achieved because we annotate the new version of the original point cloud with the parametric equations representing each part. We mainly tested our methodology in a real-world setting – the city of Genoa – which includes historical buildings and is heavily characterized by irregular ground slopes. Moreover, we present the results of urban reconstruction on part of two other cities, Matera, which has a complex morphology like Genoa, and Rotterdam.
{"title":"From aerial LiDAR point clouds to multiscale urban representation levels by a parametric resampling","authors":"","doi":"10.1016/j.cag.2024.104022","DOIUrl":"10.1016/j.cag.2024.104022","url":null,"abstract":"<div><p>Urban simulations that involve disaster prevention, urban design, and assisted navigation heavily rely on urban geometric models. While large urban areas need a lot of time to be acquired terrestrially, government organizations have already conducted massive aerial LiDAR surveys, some even at the national level. This work aims to provide a pipeline for extracting multi-scale point clouds from 2D building footprints and airborne LiDAR data, which depends on whether the points represent buildings, vegetation, or ground. We denoise the roof slopes, match the vegetation, and roughly recreate the building façades frequently hidden to aerial acquisition using a parametric representation of geometric primitives. We then carry out multiple-scale samplings of the urban geometry until a 3D urban representation can be achieved because we annotate the new version of the original point cloud with the parametric equations representing each part. We mainly tested our methodology in a real-world setting – the city of Genoa – which includes historical buildings and is heavily characterized by irregular ground slopes. Moreover, we present the results of urban reconstruction on part of two other cities, Matera, which has a complex morphology like Genoa, and Rotterdam.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0097849324001572/pdfft?md5=a617708d0acaf24ecd321d09a5821721&pid=1-s2.0-S0097849324001572-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141942922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-31DOI: 10.1016/j.cag.2024.104020
Analysis of 3D textures, also known as relief patterns is a challenging task that requires separating repetitive surface patterns from the underlying global geometry. Existing works classify entire surfaces based on one or a few patterns by extracting ad-hoc statistical properties. Unfortunately, these methods are not suitable for objects with multiple geometric textures and perform poorly on more complex shapes. In this paper, we propose a neural network for binary segmentation to infer per-point labels based on the presence of surface relief patterns. We evaluated the proposed architecture on a high resolution point cloud dataset, surpassing the state-of-the-art, while maintaining memory and computation efficiency.
{"title":"Binary segmentation of relief patterns on point clouds","authors":"","doi":"10.1016/j.cag.2024.104020","DOIUrl":"10.1016/j.cag.2024.104020","url":null,"abstract":"<div><p>Analysis of 3D textures, also known as relief patterns is a challenging task that requires separating repetitive surface patterns from the underlying global geometry. Existing works classify entire surfaces based on one or a few patterns by extracting ad-hoc statistical properties. Unfortunately, these methods are not suitable for objects with multiple geometric textures and perform poorly on more complex shapes. In this paper, we propose a neural network for binary segmentation to infer per-point labels based on the presence of surface relief patterns. We evaluated the proposed architecture on a high resolution point cloud dataset, surpassing the state-of-the-art, while maintaining memory and computation efficiency.</p></div>","PeriodicalId":50628,"journal":{"name":"Computers & Graphics-Uk","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0097849324001559/pdfft?md5=2a3d2170481b5dae4c7f729baa4b2914&pid=1-s2.0-S0097849324001559-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141942923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}