Skeleton-aware implicit function for single-view human reconstruction

The aim is to reconstruct a complete and detailed clothed human from a single-view input.Implicit function is suitable for this task because it represents fine shape details and varied topology.Current methods,however,often suffer from artefacts such as broken or disembodied body parts,missing details,or depth ambiguity due to the ambiguity and complexity of human articulation.The main issue observed by the authors is structureagnostic.To address these problems,the authors fully utilise the skinned multi-person linear(SMPL)model and propose a method using the Skeleton-aware Implicit Function(SIF).To alleviate the broken or disembodied body parts,the proposed skeleton-aware structure prior makes the skeleton awareness into an implicit function,which consists of a bone-guided sampling strategy and a skeleton-relative encoding strategy.To deal with the missing details and depth ambiguity problems,the authors’body-guided pixel-aligned feature exploits the SMPL to enhance 2D normal and depth semantic features,and the proposed feature aggregation uses the extra geometry-aware prior to enabling a more plausible merging with less noisy geometry.Additionally,SIF is also adapted to the RGB-D input,and experimental results show that SIF outperforms the state-of-the-arts methods on challenging datasets from Twindom and Thuman3.0.

3D Vector Reconstruction of the Typical Cervical Vertebra from Anatomical Sections of Korean Visible Human at the Laboratory of Clinical and Digital Anatomy of Paris Descartes University

Aim: To carry out a 3D vector reconstruction of the typical cervical vertebra from anatomical sections of the “Korean Visible Human” for educational purposes. Material and Methods: The anatomical subject was a 33-year-old Korean man who died of leukemia. He was 164 cm tall and weighed 55 kg. This man donated his body to science. Her body was frozen and cut into several anatomical sections after an MRI and CT scan. These anatomical sections were made using a special saw called a 0.2 mm thick cryomacrotome. Thus 8100 cuts were obtained. Only the sections numbered 940 to 1200 were used for our study. A segmentation by manual contouring of the different parts of the typical cervical vertebra was made using the software Winsurf version 3.5 on a laptop PC running Windows 7 equipped with a Ram of 8 gigas. Results: Our 3D vector model of the typical cervical vertebra is easily manipulated using the Acrobat 3DPDF interface. Each part of the vertebra accessible in a menu can be displayed, hidden or made transparent, and 3D labels are available as well as educational menus for learning anatomy. Conclusion: This original work constitutes a remarkable educational tool for the anatomical study of the typical cervical vertebra and can also be used as a 3D atlas for simulation purposes for training in therapeutic gestures.

Movement Function Assessment Based on Human Pose Estimation from Multi-View

Human pose estimation is a basic and critical task in the field of computer vision that involves determining the position(or spatial coordinates)of the joints of the human body in a given image or video.It is widely used in motion analysis,medical evaluation,and behavior monitoring.In this paper,the authors propose a method for multi-view human pose estimation.Two image sensors were placed orthogonally with respect to each other to capture the pose of the subject as they moved,and this yielded accurate and comprehensive results of three-dimensional(3D)motion reconstruction that helped capture their multi-directional poses.Following this,we propose a method based on 3D pose estimation to assess the similarity of the features of motion of patients with motor dysfunction by comparing differences between their range of motion and that of normal subjects.We converted these differences into Fugl–Meyer assessment(FMA)scores in order to quantify them.Finally,we implemented the proposed method in the Unity framework,and built a Virtual Reality platform that provides users with human–computer interaction to make the task more enjoyable for them and ensure their active participation in the assessment process.The goal is to provide a suitable means of assessing movement disorders without requiring the immediate supervision of a physician.

腹壁下动脉穿支皮瓣的3D可视化研究

目的为腹壁下动脉穿支皮瓣的设计与安全截取提供解剖学依据。方法 8具新鲜尸体,采用选择性颜料灌注、动脉造影及CT扫描与三维重建,重点观察腹壁下动脉肌皮穿支及其跨越正中线的有效吻合血管。然后,层次解剖观测腹前外侧壁外径≥0.5 mm的穿支,测量其管径及其走行、分支、分布情况并拍摄X线片。利用Photoshop与Scion Image软件分析穿支供血的趋向性及其供血面积。结果腹壁下动脉的出现率为100%,平均每侧发出(4.8±1.7)支肌皮穿支,直径(0.7±0.2)mm,单穿支供血面积为33cm2,单个穿支皮瓣大小为20cm×15cm。结论腹壁下动脉起源、行程及其穿支较恒定。双侧肌皮穿支间有丰富的、跨越正中线的真性吻合,具备截取跨越中线的横向跨区穿支皮瓣的解剖学基础,横向皮瓣面积可达20cm×42cm。

Development of Multi-Agent-Based Indoor 3D Reconstruction

Large-scale indoor 3D reconstruction with multiple robots faces challenges in core enabling technologies.This work contributes to a framework addressing localization,coordination,and vision processing for multi-agent reconstruction.A system architecture fusing visible light positioning,multi-agent path finding via reinforcement learning,and 360°camera techniques for 3D reconstruction is proposed.Our visible light positioning algorithm leverages existing lighting for centimeter-level localization without additional infrastructure.Meanwhile,a decentralized reinforcement learning approach is developed to solve the multi-agent path finding problem,with communications among agents optimized.Our 3D reconstruction pipeline utilizes equirectangular projection from 360°cameras to facilitate depth-independent reconstruction from posed monocular images using neural networks.Experimental validation demonstrates centimeter-level indoor navigation and 3D scene reconstruction capabilities of our framework.The challenges and limitations stemming from the above enabling technologies are discussed at the end of each corresponding section.In summary,this research advances fundamental techniques for multi-robot indoor 3D modeling,contributing to automated,data-driven applications through coordinated robot navigation,perception,and modeling.

Towards efficient and photorealistic 3D human reconstruction: A brief survey

Reconstructing 3D digital models of humans from sensory data is a long-standing problem in computer vision and graphics with a variety of applications in VR/AR,film production,and human–computer interaction,etc.While a huge amount of effort has been devoted to developing various capture hardware and reconstruction algorithms,traditional reconstruction pipelines may still suffer from high-cost capture systems and tedious capture processes,which prevent them from being easily accessible.Moreover,the dedicatedly hand-crafted pipelines are prone to reconstruction artifacts,resulting in limited visual quality.To solve these challenges,the recent trend in this area is to use deep neural networks to improve reconstruction efficiency and robustness by learning human priors from existing data.Neural network-based implicit functions have been also shown to be a favorable 3D representation compared to traditional forms like meshes and voxels.Furthermore,neural rendering has emerged as a powerful tool to achieve highly photorealistic modeling and re-rendering of humans by end-to-end optimizing the visual quality of output images.In this article,we will briefly review these advances in this fast-developing field,discuss the advantages and limitations of different approaches,and finally,share some thoughts on future research directions.

DLT算法中象平面误差对三维重构的影响

DLT算法是利用平面图象进行三维重构的广泛采用的基本算法。本文针对平面图象处理中难以避免的象坐标误差 ,讨论了各坐标误差对三维重构坐标的影响 ,由此分析了三维重构坐标对各象坐标误差的敏感程度 ,并进行了数值模拟实验。结果表明三维重构的各分坐标对象坐标误差具有不同的敏感度 ,而且与相机的空间位置有密切的联系。这说明DLT算法中虽然在理论上对相机的空间配置无特别要求 。

Sectional anatomy of the caudate lobe of liver:based on coronal and sagittal sections

To provide practical and surgical anatomy for the imaging diagnosis and surgical treatment of the disease of the caudate lobe of the liver. Methods： Based on Chinese Visible Human 1-5 data sets and assisted by 3D visualization and reconstruction, the 3D models of the upper abdomen or the liver were reconstructed and the cross-sectional images were converted to the coronal and sagittal images. The anatomy of the caudate lobe of the liver on the coronal and sagittal planes was investigated on serial planes of the upper abdomen. Results： The caudate lobe was bordered on the left by the fissura ligamenti venosi, posteriorly by the IVC, superiorly by the hepatic veins and inferiorly by the hepatic hilum. Its right and ventral borders might be obscure, with only relative borders existent. The right wall of the IVC was a good landmark to judge the relative realm of paracaval portion, and the relative ventral plane might exist between the hepatic hilum and entrance of hepatic veins. The caudate lobe could be divided into two principal regions： the left Spiegel lobe and the right paracaval portion. The caudate process, and the right rear process occurring in some individuals belonged to the right paracaval portion. The caudate lobe was blood supplied by the portal vein, which directly drained into the IVC. Conclusion： There are not definite borders for the right part of the caudate lobe, and most of the knowledge on it is based on the cast study, which may not suit for the clinical diagnosis and practice. The coronal and sagittal sections can better show the anatomic relationships between the caudate lobe, the other parts of the liver and the adjacent structures. The 3D digital visualization is an accurate and convenient study method for clinical anatomy.

首套中国男、女数字化可视人体结构数据的可视化研究

目的 实现首套中国男、女数字化可视人体结构数据的计算机可视化。方法 在获得首套 (包括 1例男性和1例女性 )数字化可视人体结构数据集 (男性为 2 5 18个横断面 ,总数据量为 90 64 8GB ;女性为 3 64 0个横断面 ,总数据量为13 0 0 4GB)后 ,分别在SGI图像工作站和P4微机上 ,先对二维图像进行处理 ,然后经过在每幅图像上预留的定标点进行对位配准。重建时采用了两种方法 ,一是体绘制 (Volumerendering)重建 ;二是面绘制 (Surfacerendering)重建。结果 在SGI工作站和微机上分别实现了男、女数字化可视人体的整体和局部可视化。并且 ,通过革新三维重建和数据处理技术 ,实现了中国首套数字化人体数据的交互式三维可视化。结论 ①经过可视化研究检验 ,本研究组采集的首套中国男、女数字化可视人体数据集符合三维可视化的要求。②本研究建立起来的中国男、女数字化可视人体数据的交互式三维可视化平台 ,形成了数字人体解剖学和虚拟外科手术的雏形。③经过数据分割、分类。

人体器官的计算机三维重建及显示

本研究应用国内计算机的设备条件,采用体素表示的表面显示法,对人体肾脏、颅及腰椎的CT图象进行了计算机三维重建和显示。对新鲜离体肾脏标本先行包埋、低温冰冻,横断连续切割和撮影,然后再行轮廓描绘并将图象输入计算机;另外选择颅和腰椎横断面的CT图象,同样输入机内。在Vax-11/730主机,S-600图象处理系统下,用FORTRAN 77编制成软件包,实现在彩色监视器的屏幕上,对上述器官进行了三维重建和显示。重建后的器官可按需要进行不同角度的旋转、剖割和透明处理。图象逼真,富有立体感。本研究为解剖学的教学和科研,为CT诊断等提供了一种新颖的、有价值的显像手段。

首例中国可视化人体心脏三维重建及临床意义

目的 对首例中国数字化可视人体的心脏进行三维重建 ,为心脏疾病的影像学诊断和外科手术提供三维解剖学依据。方法 将首例中国数字化可视人体心脏部分的薄层断面 (层厚 1.0mm )输入SGI工作站 ,经数据分割、对位重建、平滑处理和三维显示等步骤 ,完成对心脏结构的三维重建。结果 本研究完整地重建出了心脏结构 ,重建的结构能够以多结构、多彩色实体模型方式显示 ,可显示心脏内部各结构的空间位置和毗邻关系 ,可在三维空间位置上绕任意轴旋转任意角度。结论 重建出的三维图像清晰地显示了心脏内部和整体的结构 。

耳三维重建及虚拟内窥镜

目的 建立人体耳部可视化数字模型 ,探索虚拟耳内窥镜在内耳解剖研究中的作用。方法 应用首例中国数字化可视人体数据集 ,在SGI工作站上对耳部重要结构进行计算机三维重建及立体显示 ,并模仿耳内窥镜对中耳、内耳等结构进行观察。结果 成功获得耳部可视化模型 ,应用虚拟内窥镜可清楚显示中耳及内耳结构三维形态。结论 虚拟耳内窥镜观察有助于分析阐明耳内部结构的三维空间毗邻关系 ,可为耳部疾病的影像诊断及耳神经外科手术提供形态学资料。

原位牙的连续横断层解剖与可视化研究

目的 提供原位牙的断层解剖研究方法和形态学资料 ,并进行三维可视化研究 ,建立原位牙的立体形态。方法 从首例中国可视人数据集中提取全牙的断层图像 ,观察牙的形态结构 ,利用MedView1.0软件进行三维重建 ,观察牙及其周围结构的关系。结果 牙齿完整 ,能清晰显示牙及其周围解剖结构的形态及毗邻关系 ;重建结构清晰 ,能清楚显示牙在牙槽内位置和方向。结论 冰冻铣切技术能完整保留牙齿各断面 ,可作为牙断层解剖的研究手段 ;

数字虚拟中国人男性一号循环系统的三维建模

目的建立虚拟中国人男性一号血管灌注循环系统的三维模型,为解剖教学以及临床虚拟手术研究提供三维数据模型。方法对数字虚拟中国人男性一号样本进行血管灌注,对获取的彩色断层图片进行空间配准和半自动交互分割,对分割后的数据通过并行算法进行快速三维重建处理。结果对灌注后的动静脉血管和心脏建立了三维模型;通过组合动脉和静脉以及心脏模型获得了全身循环系统的三维模型,弥补了数字化虚拟人体血管模型的空白。结论经过样本的动脉灌注处理之后,在获取高分辨率的切片数据的基础上,建立了精确、完整的血管模型。

基于虚拟中国人数据集的鼻部及颞骨解剖结构三维重建

目的:为可视化虚拟人体模型鼻部及颞骨解剖结构的三维重建探索一种可行的方法。方法:利用3D-Slicer软件进行鼻部及颞骨部分解剖结构的三维重建。对单层图片进行图象分割及提取,处理后的体数据导入3D-Slicer,选择阈值进行进一步的图像分割,产生感兴趣区的标志图,进而重建出组织结构的三维表面模型。结果:成功重建了四组鼻窦,鼻中隔,中下鼻甲,颞骨,鼓室,乳突气房,乙状窦,颈内动脉的三维表面模型,并可显示不同结构间的毗邻关系与空间定位。结论:基于中国第一号虚拟人数据集,用3-D软件可以实现鼻部颞骨部分解剖结构三维可视化,便于对该部解剖结构的观察和理解。

中国数字化人体鼻部结构的三维重建和可视化

目的建立可视化人体的鼻部相关结构的三维模型。方法采用中国首例女性数字化可视人体数据集(CVH-2),选取从额窦顶到上颌窦底消失水平连续横断面图像,在计算机上利用Amira4.1软件和RadioDexter软件行三维重建的立体显示。结果重建出了鼻骨,额窦,筛窦,蝶窦,上颌窦,鼻腔,上、中、下鼻甲,鸡冠,鼻中隔,钩突,鼻泪管,颈内动脉,视神经的三维可视化模型。该模型可以任意缩放和任意角度旋转,可显示不同结构间的毗邻关系和空间构象,并可进行三维的距离和角度的测量。结论鼻部相关结构的三维可视化模型可促进对该部位解剖结构的理解和掌握,为鼻部疾病影像诊断和鼻内镜手术提供了形态学参考,并可应用于虚拟手术。

首例中国可视化人体头颈部CT影像三维重建的初步研究

目的 对首例中国可视化人体头颈部CT影像进行三维重建研究。方法 将首例中国可视化人体头颈部的轴位断层CT图像 (层厚 1mm ,连续扫描 ) ,应用SiemensCRT3 .0图像处理软件在SGIGraphics计算机工作站上进行三维重建和观察。结果 头面部结构得到良好重建 ,其面部轮廓包括鼻翼、唇、外耳廓、下颏等均能清晰显示。头颈部骨骼的精细三维重建 ,显示出颅底圆孔、卵圆孔、棘孔等细微结构。头颈部三维剖面观察可使包括垂体、脑干、颈髓、蝶窦、鼻咽等结构获得良好显示。结论 本研究实现了对首例中国可视化人体头颈部CT影像的三维重建和可视化 。

基于Visualization Toolkit的数字化人体骨骼系统的重建与可视化

在人体骨骼系统的三维可视化过程中 ,将二维CT数据重建生成理想的三维骨骼数据是非常重要的一环。作者应用可视化工具VisualizationToolkit (VTK)和VC ++实现了二维数据的三维重建、面片削减、连通性检测、三维平滑等一系列功能。与利用OpenGL等工具重建得到的骨骼数据相比 ,不但准确度和视觉效果有了显著改善 ,数据量也大大减小。VTK在人体骨骼系统的重建及处理工作中取得的良好效果表明 ,它是医学图像重建和处理的有力工具之一 ,具有使用灵活 ,功能强大的优点 ,值得推广。

脑干、三叉神经及大脑动脉环的可视化研究

目的 建立人体脑干、三叉神经及大脑动脉环的可视化数字模型。方法 采用首例中国数字化可视人体数据集 ,在SGI工作站上对脑干及其周围毗邻结构进行计算机三维重建并立体显示。结果 获得人体脑干、三叉神经及大脑动脉环等器官组织的三维重建结构 ,可对其进行任意径线和角度的适时三维测量。结论 首例中国数字化可视人体数据集能够提供完整而精确的解剖断面数据 ,脑干及其毗邻的三叉神经、大脑动脉环的可视化模型准确反映出该区域复杂的解剖学结构特点及其相邻器官间的空间毗邻关系 。

探索牙齿模型重建与数控加工技术

介绍了逆向工程技术在人体牙齿造型中的应用,利用非接触式三维激光扫描仪采集牙齿点云数据,以逆向工程软件Imageware为平台进行数据处理,开发牙齿的三维重建系统原型,并对重构的逆向模型与原始点云进行3D检测和偏差分析,实现了人体牙齿的三维重建和分析,为整体全金属牙齿的制造提供了依据和技术支持。