Child body shape measurement using depth cameras and a statistical body shape model

We present a new method for rapidly measuring child body shapes from noisy, incomplete data captured from low-cost depth cameras. This method fits the data using a statistical body shape model (SBSM) to find a complete avatar in the realistic body shape space. The method also predicts a set of standard anthropometric data for a specific subject without measuring dimensions directly from the fitted model. Since the SBSM was developed using principal component (PC) analysis, we formulate an optimisation problem to fit the model in which the degrees of freedom are defined in PC-score space. The mean unsigned distance between the fitted-model based on depth-camera data and the high-resolution laser scan data was 9.4 mm with a standard deviation (SD) of 5.1 mm. For the torso, the mean distance was 2.9 mm (SD 1.4 mm). The correlations between standard anthropometric dimensions predicted by the SBSM and manually measured dimensions exceeded 0.9.     

Parametric body shape model of standing children aged 3–11 years

A statistical body shape model (SBSM) for children was developed for generating a child body shape with desired anthropometric parameters. A standardised template mesh was fit to whole-body laser scan data from 137 children aged 3–11 years. The mesh coordinates along with a set of surface landmarks and 27 manually measured anthropometric variables were analysed using principal component (PC) analysis. PC scores were associated with anthropometric predictors such as stature, body mass index (BMI) and ratio of erect sitting height to stature (SHS) using a regression model. When the original scan data were compared with the predictions of the SBSM using each subject's stature, BMI and SHS, the mean absolute error was 10.4 ± 5.8 mm, and 95th percentile error was 24.0 ± 18.5 mm. The model, publicly available online, will have utility for a wide range of applications.

Practitioner Summary: A statistical body shape model for children helps to account for inter-individual variability in body shapes as well as anthropometric dimensions. This parametric modelling approach is useful for reliable prediction of the body shape of a specific child with a few given predictors such as stature, body mass index and age.     

个性化三维人体模型快速建模方法

采用模型重用的思想,通过输入21个人体测量学参数对标准人体模型进行编辑,实时获得相应体型的个性化三维人体模型．该方法使得编辑过程能够实时完成;生成的人体模型可以方便地驱动;精选的21个人体测量学参数覆盖了人体各处的细节,能够比较完整地描述人体的外形特征,满足对人体模型个性化的需求．     

Taiwanese adult foot shape classification using 3D scanning data

This study classifies the foot shapes of Taiwanese using 3D foot scanning data from 2000 males and 1000 females. Nine foot dimensions relative to foot length and absolute measures in the common foot length categories were applied to compare the gender differences. Using foot breadth in % foot length (% FL), ball of foot length in % FL and arch height in % FL as feature parameters, three foot shape types for males and females can be classified. Significant gender differences were found in seven of the nine foot dimensions. Females had greater ball of foot length than males (0.2% FL). When comparing feet of the same foot length, males had greater breadth, girth and height dimensions than females, except for toe height. In addition, ethnic differences in foot shape were also observed. The findings can provide very useful information for building gender-specific shoe lasts and designing footwear insoles.     

Parametric 3D modeling of young women's lower bodies based on shape classification

Three-dimensional (3D) human body modeling is an important research direction in the field of clothing virtual design. On the basis of 3D human body scanning, this paper studied a method to build a 3D parametric lower body model according to body classification. The research includes three main parts. (1) Anthropometry and body shape classification. We randomly selected 333 young women ages 18–25 years old in Northeast China as the experimental sample. Then we divided the lower body shape into three categories using principal component analysis and K-means clustering. (2) Determination of feature cross sections and points, and reconstruction of feature curves. According to the average values of each body type, we obtained the mean reference body by Euclidean distance method. We determined feature cross sections and points, and extracted the 3D coordinates of the feature points of the mean reference body to reconstruct the feature curves. (3) The surface lofting and establishment of parametric 3D lower body model. According to the shape characteristics of the lower body, we constructed the guiding lines for the crotch and lower limbs, and established parametric lower body models for three body types.Relevance to industry3D human modeling is an important part of garment industry digitization. This research provides an effective way to construct a parametric 3D lower body model. The method offers a reference for the parametric virtual human modeling and virtual fitting of trousers.     

辅助身份认证的局部形状上下文手形认证算法

随着技术的发展和对安全性要求的提高,单一生物特征已经很难满足高度机密身份认证的需求,需要进行多特征身份认证,因此提出一种可以用做辅助认证的手形认证算法.该算法不限制图像采集背景,实验中采用了相对难处理的白色背景.先粗分割提取手形样本,后根据样本特征细分割得到手形轮廓,该分割算法能够在含阴影的图像中准确地提取手形轮廓,具有高自适应性和可移植性;同时提出了局部形状上下文手形认证算法,采用局部均匀采样,在局部范围内提取手形的形状上下文特征,根据该特征进行匹配认证.该方法的认证等错误率为3.15％,与其他形状上下文算法相比,在相同时间代价下,等错误率降低了1.5％ ～5％.     

Research on lower body shape of late pregnant women in Shanghai area of China

Anthropometric data, especially the data of lower body of late-pregnant women, has become an immediate need for ergonomic design of maternity products, such as clothing, related motherhood supplies, maternity support products, and so on. So 55 late pregnant women in Shanghai area of China were randomly selected for this lower body shape research. By anthropometric measurement method 18 dimensions were measured to characterize lower body shape of late pregnant women. Mean values, standard deviations (SD), coefficients of variation, and percentiles for each variable were estimated. It was found that the morphology of hip and abdomen mostly influenced the lower body shape. Then according to the characters of hip and abdomen, the late pregnant women's lower body shapes were divided into two types. Moreover this paper also analyzed the change trend of lower body shape along late pregnancy months (7 to 9th months). As a result of this research, the late pregnant women's lower body shapes were described from different aspects which were thought to provide a guide for the maternity products design.Relevance to industryThe anthropometric data is essential to design reasonable and professional maternity products for late pregnant women, such as maternity support products, maternity clothing and so on. Especially this study can benefit the maternity garment industry. Moreover utilization of the anthropometric data, product designers would be able to outfit to a wider range of target users.     

Sex-related differences in foot shape

The purpose of the study was to investigate sex-related differences in foot morphology. In total, 847 subjects were scanned using a 3-D-footscanner. Three different analysis methods were used: (1) comparisons were made for absolute foot measures within 250–270 mm foot length (FL); (2) and for averaged measures (% FL) across all sizes; (3) the feet were then classified using a cluster analysis. Within 250–270 mm FL, male feet were wider and higher (mean differences (MD) 1.3–5.9 mm). No relevant sex-related differences could be found in the comparison of averaged measures (MD 0.3–0.6% FL). Foot types were categorised into voluminous, flat-pointed and slender. Shorter feet were more often voluminous, longer feet were more likely to be narrow and flat. However, the definition of ‘short’ and ‘long’ was sex-related; thus, allometry of foot measures was different. For shoe design, measures should be derived for each size and sex separately. Different foot types should be considered to account for the variety in foot shape. Improper footwear can cause foot pain and deformity. Therefore, knowledge of sex-related differences in foot measures is important to assist proper shoe fit in both men and women. The present study supplements the field of knowledge within this context with recommendations for the manufacturing of shoes.     

An updated estimate of the body dimensions of US children

Anthropometric data from children are important for product design and the promulgation of safety standards. The last major detailed study of child anthropometry in the USA was conducted more than 30 years ago. Subsequent demographic changes and the increased prevalence of overweight and obesity render those data increasingly obsolete. A new, large-scale anthropometric survey is needed. As an interim step, a new anthropometric synthesis technique was used to create a virtual population of modern children, each described by 84 anthropometric measures. A subset of these data was validated against limited modern data. Comparisons with data from the 1970s showed significant changes in measures of width and circumference of the torso, arms and legs. Measures of length and measurements of the head, face, hands and feet exhibited little change. The new virtual population provides guidance for a comprehensive child anthropometry survey and could improve safety and accommodation in product design.

Practitioner Summary: This research reviews the inadequacies of available sources of US child anthropometry as a result of the rise in the rates of overweight and obesity. A new synthesised database of detailed modern child anthropometry was created and validated. The results quantify changes in US child body dimensions since the 1970s.     

典型的基于区域的形状表示方法比较

目的 形状的表示和匹配是计算机视觉和模式识别领域的重要问题。在基于区域的形状表示方法中出现了一批典型的方法,包括Hu不变矩方法（Hu不变矩）、角径向变换方法（ART方法）、通用傅里叶描述子方法（GFD方法）、拉东柱状图方法（HRT方法）和多尺度积分不变量方法（MSⅡ方法）等。由于这些方法出现的时间跨度长且在以往的对比研究中研究维度单一,因此需要对这些方法的综合性能做一个全面的比较分析和研究,为下一步的理论研究和实际应用提供方向和指导。方法 采用3个基准形状库,包括简单几何图形形状库、MPEG-7形状库和汽车商标形状库,从3个维度,包括检索得分、检索稳定性和方法的计算复杂度,使用加权综合评估模型对典型的基于区域的形状表示方法进行比较分析,综合评估各种方法的综合性能指标。结果 在综合性能上GFD方法具有最优的效果,其次是ART方法;由于HRT方法在匹配计算阶段具有较高的时间复杂度,在大规模形状库匹配的场景下性能会下降;Hu不变矩和MSⅡ方法的实验效果均不理想。通过比较研究还发现,将形状正交投影到正交基函数是提取形状视觉特征的有效方式。进一步猜想,将图像正交投影到正交基函数也是提取图像视觉特征的有效方式。因此,未来的研究中,寻找理想的正交基函数是提取形状乃至图像视觉特征的重要研究方向。结论 在5种比较研究的方法中,GFD方法和ART方法在综合效果要好于HRT方法、Hu不变矩方法和MSⅡ方法,并且寻找理想的正交基函数是未来形状表示的重要研究方向。     

Development of sizing structure for fall arrest harness design

Updated harness designs are needed to accommodate diverse populations in the current workforce. This paper determined an improved fall-arrest harness sizing scheme and strap-length configurations for harness design. A 3-D elliptic Fourier analysis (EFA) procedure with 123 coefficients was developed to quantify torso-shape effect on harness fit, based on 3-D data of 108 women and 108 men. The EFA coefficients were then applied to 600 representative body scans from a national database of 2382 participants to establish an improved sizing system. Study outcomes suggested a more upward back D-ring location for women than current unisex designs to accommodate female torso form and mitigate their fit problem. Results also suggested an improved system of three sizes for women and three sizes for men. New harness sizing charts for women and men were proposed accordingly. Using the most current 3-D whole-body digital scanning technology, this study assembled data from a US workforce to establish an improved fall-arrest harness sizing system and strap configurations for men and women. The information is useful for new generation harness designs to reduce the risk of worker injury.     

A new definition of shape similarity

Two reference points of a region are defined which do not depend on the position, size and orientation of the region. Reference points are used to get borders on the basis of which the shape distance and shape similarity are defined.     

使用形状变化描述三维模型

针对三维模型检索中的形状特征提取问题,提出利用三维模型自身形状变化信息构造形状特征描述符的方法.首先选择一组等间距互相平行的平面切割三维模型,得到三维模型的切片集合;然后定义相邻切片的 差来描述切片间的形状变化,并通过所有相邻切片间的差值来反映三维模型自身的形状变化,以此作为三维模型的形状特征描述符.该方法与三维模型的旋转、平移无关,同时不依赖于模型的点云分布,并且精简模型三角面片对算法的影响较小.实验结果验证了该方法的有效性.     

Comparison of measured and self-reported anthropometric information among firefighters: implications and applications

This study evaluated the accuracy of self-reported body weight and height compared to measured values among firefighters and identified factors associated with reporting error. A total of 863 male and 88 female firefighters in four US regions participated in the study. The results showed that both men and women underestimated their body weight ( ? 0.4 ± 4.1, ? 1.1 ± 3.6 kg) and overestimated their height (29 ± 18 , 17 ± 16 mm). Women underestimated more than men on weight (p = 0.022) and men overestimated more than women on height (p < 0.001). Reporting errors on weight were increased with overweight status (p < 0.001) and were disproportionate among subgroups. About 27% men and 24% women had reporting errors on weight greater than ± 2.2 kg, and 59% men and 28% women had reporting errors on height greater than 25 mm.

Practitioner Summary: This study along with literature revealed that the self-reported approach is not a sustainable option for anthropometric surveys, even for gathering data from physically active professional groups, such as firefighters, who presumably are knowledgeable of their body dimensions. Self-reported anthropometric information is undependable in important population subgroups.     

Measurement error in statistical models of shape

Active shape models (ASMs) are popular and sophisticated methods of extracting features in (especially medical) images. Here we analyse the error in placing ASM points on the boundary of the feature. By using replications, a corrected covariance matrix is presented that should reduce the effects of placement error. We show analytically and via simulations that the cumulative variability for a given number of eigenvalues retained in principal components analysis (PCA) ought to be reduced by increasing levels of point-placement error. Results for predicted errors are in excellent agreement with the set-up parameters of two simulated shapes and with anecdotal evidence from the trained experts for real data taken from the OSTEODENT project. We derive an equation for the reliability of placing the points and we find values of 0.79 and 0.85 (where 0 = bad and 1 = good) for the two clinical experts for the OSTEODENT data. These analyses help us to understand the sources and effects of measurement error in shape models.     

水稻叶片形态日变化过程可视化模拟研究

在实验测定的基础上,分析了水稻叶片几何形态随逐日生长时间动态变化的规律,分别构建了叶长变化模型、叶长与叶宽关系模型、茎叶夹角变化模型、以及不同叶位最终叶长模型和叶片出叶时间模型。结合水稻叶片的三维形态模型,在计算机上编程实现了水稻叶片器官形态逐日动态生长变化过程的可视化模拟,具有较强的真实感,为构建虚拟水稻生长系统奠定了基础。