A protocol for evaluating the accuracy of 3D body scanners

Abstract

Scan-derived landmarks locations and surface shapes are more and more used, but there is no commonly accepted protocol for evaluating the accuracy of these measurements. Therefore we propose a protocol for evaluating the accuracy of surface shape and the repeatability of scan-derived landmark locations. According to existing Japanese and German domestic standards, we propose to use an artefact (e.g. sphere with diameter of about 120 mm) calibrated very accurately for evaluating the accuracy of scanner-systems. For evaluating the repeatability of landmark locations, we propose to use an anthropomorphic dummy with landmark locations premarked. These test objects are measured by a 3D body scanner to be evaluated. Evaluation parameters such as trueness, precision, and repeatability are calculated from the measured data. A round-robin test was conducted in six different institutes using 17 body/head/foot scanners produced by eight companies. The purposes of the roundrobin test were to evaluate the availability of test objects to different body scanners, and to examine the measurement locations of test objects and quality parameters to be reported. As a result, the proposed test objects could be measured and the data exported by all scanner systems except one, which could not export the ball measurement. For a comparative purpose, a figure of measured surface might be useful.

Development of a positioning aid to reduce postural variability and errors in 3D whole body scan measurements

“…Due to the fact that this technical variability is system inherent it constitutes the minimum variability that can be achieved with the experimental set-up and therefore serves as a reference to the effectiveness of the positioning aid. Thus, the study included a reference test comprising of ten repeated scans of a rigid mannequin following the protocol proposed by Kouchi et al (2012). The mannequin was outfitted with the same attire as the study participants and was placed in the standard standing posture with the feet 35 cm apart as stipulated by the scanner manufacturer (8).…”

Avaliação de posturas para antropometria digital considerando tempo, conforto e qualidade da malha obtida

“…In performing large-scale digital anthropometric studies, using 3D scanning, besides the choices of equipment (KOUCHI, 2012) and accompanying software, the researchers must consider the user participation (SCHWARZ-MUELLER; MARSHALL; SUMMERSKILL, 2018; SILVA; SALVALAIO; KINDLEIN, 2010) and also their own post-processing work (HEYMSFIELD et al, 2018;CUI;STRICKER, 2011). So, we can consider that in the scanning process the participants influence directly the quality of the mesh obtained and that the quality of the mesh accounts for most of the post-processing time and quality of the measurements taken.…”

“…Some of these limitations might be mitigated when using more than one Kinect at a time, so to cover more body surface area and ultimately take less time scanning (PARK; REED, 2014). Nevertheless, when adding more Kinects to the study, other concerns arise such as the alignment of the meshes (HIRSHBERG et al, 2011), calibration of the equipment (HEYMSFIELD et al, 2018;KOUCHI, 2012) and structural support (SCHWARZ-MUELLER; MARSHALL; SUMMERSKILL, 2018) to hold all the equipment in fixed positions or moving together. In previous work, we developed a scanning platform that was used in this study to attempt to solve some of the sensors positioning and moving together issues.…”

1C1-2 Analysis and Usability Testing of the 3D Scanning Method for Anthropometric Measurement of the Elderly

“…In order to standardize measurement protocol, some researches have been conducted focusing on the reliability of both manual and 3D scanning measurements [13][14][15]. Together with reliability, measurement procedure for a large-scaled survey is also needed to be considered.…”