3D Reconstruction from 2D Line Drawings only with Visible Vertices and Edges

The human vision system can reconstruct a 3D object easily from single 2D line drawings even if the hidden lines of the object are invisible. Now, there are many methods have emulated this ability, but when the hidden lines of the object are invisible, these methods cannot reconstruct a complete 3D object. Therefore, we put forward a new algorithm to settle this hard problem. Our approach consists of two steps： （1） infer the invisible vertices and edges to complete the line drawing, （2） propose a vertex-based optimization method to reconstruct a 3D object.

Drishti Paint 3.2:a new open-source tool for both 2D and 3D segmentation

X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread application,developing an efficient and user-friendly method for segmenting CT data continues to be a formidable challenge in the field.Most CT data segmentation software operates on 2D interfaces,which limits flexibility for real-time adjustments in 3D segmentation.Here,we introduce Curves Mode in Drishti Paint 3.2,an open-source tool for CT data segmentation.Drishti Paint 3.2 allows users to manually or semi-automatically segment the CT data in both 2D and 3D environments,providing a novel solution for revisualizing CT data in paleontological studies.

3D object reconstruction by point coordinates of 2D line drawings

It is a research subject in computer vision to 3D reconstruction of an object represented by a single 2D line drawing. Previous works on 3D reconstruction from 2D line drawings focus on objects with lines, plane, view, and so on. This paper mainly studies the 3D reconstruction from 2D line drawings. Besides, a new approach is proposed： it is that for the research of the point coordinates of 2D line drawings, so as to achieve the object reconstruction by the reconstruction of point coordinates. The reconstruction process includes： （1） the collection of point coordinates （X,Y） of 2D line drawings; （2） the derivation of mathematical formula about the reconstruction of the point of 2D line drawings, and calculating the corresponding point of the 3D coordinates; （3） the regeneration of 3D graphics with 3D points; （4） analyze error by the proportional of parallel of axonometric projection, in order to prove the accuracy of the method.

2D/3D多模态医学图像配准算法研究

2D/3D多模态配准在医学影像导航手术中起着重要作用,主要用于提供术前三维图像和术中二维图像的实时信息,帮助医生精准定位病灶,规划手术路径,从而提高手术的安全性和效率。提出了一种2D/3D多模态医学图像配准算法,首先利用Swin Transformer优秀的特征提取能力,构建了初始姿态估计模型,实现姿态参数的快速预测;接着,为了提升整个配准方法的鲁棒性,引入基于Grangeat关系的粗配准方法;最后设计了基于梯度下降的精配准模块,以提升整个配准过程的精确性,且在该模块将Sobel微分算子与归一化互相关结合,提升了参数优化过程中的灵敏度。实验结果表明,所提配准方法在正位和侧位配准中的误差满足配准要求,配准成功率有显著提升。

基于Lie群表示的保体积2D-3D点集配准算法

2D-3D点集配准的目标是寻找三维原始点集与二维目标投影点集之间的对应关系和最优变换.为了给出配准问题的解析解,避免投影引起的体积退化,提出基于Lie群表示的保体积2D-3D点集配准算法.首先,考虑投影矩阵和旋转矩阵的非交换性,引入Lie群表示,将配准问题形式化为一个Lie群优化问题.利用局部线性化方法,将Lie群优化问题转化为一个可计算的二次规划问题.其次,为了避免体积退化,考虑约束变换后的三维点集的投影与二维目标点集的投影具有相同的体积.为便于计算,引入Jensen-Bregman LogDet散度作为保体积正则项,将计算点集的体积差异转化为计算协方差矩阵之间的差异.然后,通过交替求解对应关系和最优变换,形成完整且可解的迭代策略.最后,在两个经典数据集上进行对比实验和消融实验,验证了该算法的精确性和有效性.

荧光分子断层成像与计算机断层成像的2D/3D配准方法研究

针对荧光分子断层成像(fluorescence molecular tomography,FMT)中的二维光学图像与三维计算机断层成像(computed tomography,CT)图像在维度和风格等方面的差异导致配准困难的问题,本研究提出了一种基于任务回归粗配准及梯度下降精配准的两阶段配准方法。在粗配准阶段,本研究提出了目标姿态预测模型RR-Net,实现对初始位姿参数的快速估计;在精配准阶段,基于可微成像渲染模块,在粗配准参数的基础上进行迭代训练,进一步提高配准精度。本研究在公开小鼠数据集及实验室自采数据共238140张轮廓图像中验证了该配准方法的有效性。实验结果显示,本研究提出的2D/3D配准方法在FMT光学图像和CT图像配准中,相似系数为0.96±0.03,平均目标配准误差为(1.14±0.83)mm。该方法的配准效果及稳定性均优于传统方法。

3D/2D血管配准的研究进展及临床应用现状

3D/2D血管配准是将不同模态下的血管影像通过特定的配准算法进行空间、时间上的对齐。这项技术实现了不同模态图像之间的优势互补,是医学影像学领域的重大突破。2D影像资料主要通过有创血管造影获得,3D影像主要来自CT、MRI、超声等。3D/2D血管配准可将两种成像技术所获得的血管解剖结构、血管管腔内信息融合起来,为手术方案的制定、术中定位提供重要依据。在临床手术中,主要将其运用于血管介入治疗以及肿瘤切除领域。本文就3D/2D血管配准的研究进展及临床应用现状进行综述。

基于轮廓点相似性测度的2D-3D医学图像配准算法

针对传统配准算法无法适用于成像模糊、对比度低的X光医学图像的问题,本文提出一种基于轮廓点相似性测度的配准技术.首先引入分块双阈值增强策略来提取DRR图像和X光图像的边缘轮廓信息;其次,采用高斯加权欧氏距离计算图像轮廓的相似度;最后通过平衡优化器算法进行迭代优化,得到最优的位姿参数.实验结果表明:本文算法能够精确提取模糊X光图像的边缘轮廓信息,而且可以准确评估其与CT数据的相似度,平均配准成功率超过94%,算法效率和鲁棒性优于传统算法,可用于医疗诊断、放射疗法、图像引导手术等医学活动.

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.

3D and 2D topographic correction to estimated geothermal gradient from the base of gas hydrate stability zone in the Andaman Forearc Basin

Methane gas hydrate related bottom-simulating reflectors(BSRs)are imaged based on the in-line and cross-line multi-channel seismic(MCS)data from the Andaman Forearc Basin.The depth of the BSR depends on pressure and temperature and pore water salinity.With these assumptions,the BSR depth can be used to estimate the geothermal gradient(GTG)based on the availability of in-situ temperature measurements.This calculation is done assuming a 1D conductive model based on available in-situ temperature measurement at site NGHP-01-17 in the study area.However,in the presence of seafloor topography,the conductive temperature field in the subsurface is affected by lateral refraction of heat,which focuses heat in topographic lows and away from topographic highs.The 1D estimate of GTG in the Andaman Forearc Basin has been validated by drilling results from the NGHP-01 expedition.2D analytic modeling to estimate the effects of topography is performed earlier along selected seismic profiles in the study area.The study extended to estimate the effect of topography in 3D using a numerical model.The corrected GTG data allow us to determine GTG values free of topographic effect.The difference between the estimated GTG and values corrected for the 3D topographic effect varies up to~5℃/km.These conclude that the topographic correction is relatively small compared to other uncertainties in the 1D model and that apparent GTG determined with the 1D model captures the major features,although the correction is needed prior to interpreting subtle features of the derived GTG maps.

Multi-View Image-Based 3D Reconstruction in Indoor Scenes:A Survey

Three-dimensional reconstruction technology plays an important role in indoor scenes by converting objects and structures in indoor environments into accurate 3D models using multi-view RGB images.It offers a wide range of applications in fields such as virtual reality,augmented reality,indoor navigation,and game development.Existing methods based on multi-view RGB images have made significant progress in 3D reconstruction.These image-based reconstruction methods not only possess good expressive power and generalization performance,but also handle complex geometric shapes and textures effectively.Despite facing challenges such as lighting variations,occlusion,and texture loss in indoor scenes,these challenges can be effectively addressed through deep neural networks,neural implicit surface representations,and other techniques.The technology of indoor 3D reconstruction based on multi-view RGB images has a promising future.It not only provides immersive and interactive virtual experiences but also brings convenience and innovation to indoor navigation,interior design,and virtual tours.As the technology evolves,these image-based reconstruction methods will be further improved to provide higher quality and more accurate solutions to indoor scene reconstruction.

基于有限元的双唇橡胶密封的3D-2D耦合仿真分析方法研究

以某混动车型为例,通过有限元软件Abaqus建立车载PTC陶瓷电阻加热器上下法兰面的双唇橡胶模型,通过3D-2D耦合仿真的方法,考虑了在螺栓力、温度、压强多因素综合影响下的密封情况。结果表明,通过3D有限元模型计算,随着温度与压强的升高,上下法兰面会有张开量,其中压强的占比约为温度的3倍;将此张开量代入2D有限元模型,修正橡胶的压缩高度,可得到与实际更接近的密封结果。研究结果表明,通过3D-2D耦合仿真的方法,可以更精确地模拟橡胶在实际工作载荷下的密封情况,使在开发前期识别风险,提供先验性知识。

Clinical Outcomes of Complete Mesocolic Excision for Right-Sided Colon Cancer Using 3D Laparoscopy versus 2D Laparoscopy

Objective:To study the clinical outcomes of complete mesocolic excision(CME)for right-sided colon cancer using 3D(three-dimensional)laparoscopy compared to 2D(two-dimensional)laparoscopy.Methods:From January 2022 to December 2023,58 patients with right-sided colon cancer treated at the Affiliated Hospital of Hebei Engineering University were randomly divided into a 3D laparoscopy group(observation group)and a 2D laparoscopy group(control group),with 29 patients in each group.Intraoperative blood loss,postoperative time to first flatulence,length of hospital stay,and incidence of complications in both groups were recorded.Results:There was a statistically significant difference in intraoperative blood loss between the two groups(P<0.05).There was no statistically significant difference in the time to first flatulence between the groups(P>0.05).However,there was a statistically significant difference in the length of hospital stay(P<0.05)and the incidence of complications(P<0.05)between the two groups.Conclusion:3D laparoscopy for CME can reduce intraoperative blood loss,shorten hospital stay,and decrease postoperative complications,showing significant clinical advantages over traditional 2D laparoscopy.

3D与2D腹腔镜根治术对比于开腹术治疗原发性肝癌的疗效分析

评价原发性肝癌(缩写=HCC)实行3D/2D腹腔镜根治术、开腹术的临床疗效。方法 选择2年间入院的99例HCC患者,摸球均分,一组予用3D-腹腔镜根治术,二组予用2D-腹腔镜根治术;三组予用开腹术,较比疗效。结果 组间治疗后的所有指标相比,均是P<0.05。结论 3D-腹腔镜根治术相比于2D腹腔镜以及开腹术而言,其总体疗效更佳,可以优化手术指标,改善肝功能,而且并发症更少,预后也较佳。

3D腹腔镜与2D腹腔镜下全结肠系膜切除术治疗右半结肠癌的临床效果观察

目的探究3D腹腔镜与2D腹腔镜下全结肠系膜切除术(CME)治疗右半结肠癌的效果,为临床治疗提供参考。方法选取2021年1月至2023年3月宣城市人民医院收治的68例右半结肠癌患者为研究对象,进行回顾性分析,根据手术方法不同分为2D腹腔镜组(30例)和3D腹腔镜组(38例)。比较两组患者围手术期指标、肿瘤标志物水平、炎症反应指标水平、并发症发生情况。结果3D腹腔镜组患者手术时间短于2D腹腔镜组(P<0.05);两组患者术中出血量、淋巴结清扫数目、术后肛门首次排气时间、住院时间比较,差异均无统计学意义(均P>0.05)。术后,两组患者糖类抗原125(CA125)、糖类抗原199(CA199)、癌胚抗原(CEA)水平均低于术前,但组间比较,差异均无统计学意义(均P>0.05);两组患者C反应蛋白(CRP)、白细胞计数(WBC)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平均高于术前,且3D腹腔镜组均低于2D腹腔镜组(均P<0.05);两组患者并发症总发生率比较,差异无统计学意义(P>0.05)。结论3D腹腔镜下CME与2D腹腔镜下CME治疗右半结肠癌效果相当,均无明显并发症,且3D腹腔镜下CME手术时间更短,对患者造成的影响更小。

SAR regional all-azimuth observation orbit design for target 3D reconstruction

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

3D腹腔镜与2D腹腔镜宫颈癌根治术的比较研究

目的比较3D腹腔镜与传统2D腹腔镜宫颈癌根治术的手术结果和临床评价,以期为临床决策提供医学证据。方法 2013年8月～2014年10月,我院采用3D高清腹腔镜（3D组,18例）或2D高清腹腔镜（2D组,20例）对早期宫颈癌（Ⅰ～ⅡA期）行广泛性子宫切除＋盆腔淋巴结清扫术,回顾性对比2组手术时间、术中失血量、住院费用。术后术者和助手完成对3D腹腔镜设备临床评价的问卷调查。结果所有手术均在腹腔镜下顺利完成,无中转开腹。术中出血量3D组明显低于2D组[（73.9±47.5）ml vs.（134.5±69.8）ml,t=-3.094,P=0.004]。2组手术时间、盆腔淋巴结切除数、手术并发症、术后排气时间、术后腹腔引流量、术后住院时间、住院总费用差异无显著性（P〉0.05）。术者评价3D腹腔镜可提供三维立体手术视野和精确的空间立体定位,使解剖层次清晰,利于精细解剖分离和体内缝合。结论 3D高清腹腔镜拥有传统2D腹腔镜系统所不具有的深度知觉和空间定位感,给术者提供更优越的高清立体视野及更确切的手术操作环境,减少术中出血量,不增加手术时间、手术并发症及额外的手术费用,是安全、有效、舒适的。

3D腹腔镜与2D腹腔镜肝切除术的对比研究

目的探讨3D腹腔镜在肝切除术的临床应用价值。方法收集2013年10月至2015年8月46例肝脏肿瘤腹腔镜肝切除术患者的临床资料,包括3D腹腔镜组22例和2D腹腔镜组24例,分析比较两组肝切除术方式、手术时间、术中出血量、术后住院时间、术后并发症等指标。结果 3D腹腔镜组与2D腹腔组肝切除术手术方式大部分肝切除术27.3%(6例)和25%(6例),小部分肝切除术68.2%(15例)和70.8%(17例),手术方式比较差异性无统计学意义。3D腹腔镜组肝切除术手术时间短于2D腹腔镜组(150±62 min vs 205±94 min,P=0.024),差异有统计学意义(P<0.05)。3D腹腔镜组与2D腹腔镜组术中出血量(267±233 ml vs 289±265 ml,P=0.774),术后住院时间(7.8±2.7 d vs 8.2±3.2 d,P=0.936),并发症发生情况(18.2%vs 25%,P=0.575),差异比较均无统计学意义。结论与2D腹腔镜比较,3D腹腔镜下清晰的三维立体视觉,解剖层次更清晰可辨,有助于肝切除术精细操作,缩短手术时间。

3D腹腔镜与2D腹腔镜在前列腺癌根治术中的对比:回顾性队列研究（英文）

目的对3D腹腔镜与2D腹腔镜在前列腺癌根治术中的围手术期结果、功能性及肿瘤相关性结果进行比较。方法从2014年2月至2016年1月,72位临床局限性前列腺癌患者接受了腹腔镜下前列腺根治术,手术均由同一名有经验的术者操作完成。收集及评估患者的临床基本特征,围手术期结果,功能及肿瘤相关结果。结果 36位病人接受了3D腹腔镜前列腺癌根治术,另外36位病人接受了2D腹腔镜前列腺癌根治术。3D腹腔镜组比2D腹腔镜组手术时间短(167 min vs 218 min,P<0.001),平均出血量少(86.11 m L vs 177.78 m L,P<0.001),且两组术后3个月尿控率有统计学差异(88.89%vs 63.89%,P=0.026)。两组间手术并发症、性功能恢复及无生化复发率无明显差异。结论与2D腹腔镜下前列腺癌根治术相比,3D腹腔镜下前列腺癌根治术的手术时间更短,出血更少,术后早期尿控情况更好。

3D与2D全腹腔镜中间入路完整结肠系膜切除右半结肠癌根治术的对比分析

目的探讨3D腹腔镜在全腹腔镜中间入路完整结肠系膜切除右半结肠癌根治术中的优势。方法回顾性分析比较108例3D和2D全腹腔镜中间入路完整结肠系膜切除右半结肠癌根治术患者的临床资料,并将其分为3D腹腔镜组(46例)和2D腹腔镜组(62例)。结果 3D腹腔镜组第2步(缝合)手术时间、术中失血量均小于2D腹腔镜组,而在深度知觉和腔内操作(缝合及打结)难易程度优于2D腹腔镜组(P <0.05)。结论 3D腹腔镜系统在全腹腔镜中间入路完整结肠系膜切除右半结肠癌根治术中,可为术者提供清晰立体的手术画面、减少手术时间和出血量,有助于缝合时持针、打结等操作,经验丰富的外科医生亦可从3D腹腔镜系统中获益。