MVLS College, Faculty of Medicine, Biotechnology and Craniofacial Sciences Research Group, Glasgow University Dental Hospital & School, UK.
Int J Oral Maxillofac Surg. 2013 Jan;42(1):9-18. doi: 10.1016/j.ijom.2012.10.035. Epub 2012 Dec 4.
The aim of this study was to validate the automatic tracking of facial landmarks in 3D image sequences. 32 subjects (16 males and 16 females) aged 18-35 years were recruited. 23 anthropometric landmarks were marked on the face of each subject with non-permanent ink using a 0.5mm pen. The subjects were asked to perform three facial animations (maximal smile, lip purse and cheek puff) from rest position. Each animation was captured by the 3D imaging system. A single operator manually digitised the landmarks on the 3D facial models and their locations were compared with those of the automatically tracked ones. To investigate the accuracy of manual digitisation, the operator re-digitised the same set of 3D images of 10 subjects (5 male and 5 female) at 1 month interval. The discrepancies in x, y and z coordinates between the 3D position of the manual digitised landmarks and that of the automatic tracked facial landmarks were within 0.17mm. The mean distance between the manually digitised and the automatically tracked landmarks using the tracking software was within 0.55 mm. The automatic tracking of facial landmarks demonstrated satisfactory accuracy which would facilitate the analysis of the dynamic motion during facial animations.
本研究旨在验证 3D 图像序列中面部关键点的自动跟踪。共招募了 32 名 18-35 岁的受试者（16 名男性和 16 名女性）。使用 0.5 毫米的笔，在每个受试者的脸上用非永久性墨水标记 23 个人体测量标志点。要求受试者从静止位置进行三种面部动画（最大微笑、唇缩和脸颊膨出）。每个动画都由 3D 成像系统捕获。一名操作人员手动对 3D 面部模型上的标志点进行数字化，并将其位置与自动跟踪的标志点进行比较。为了研究手动数字化的准确性，操作人员在 1 个月的间隔内重新对 10 名受试者（5 名男性和 5 名女性）的同一组 3D 图像进行数字化。手动数字化标志点的 3D 位置与自动跟踪的面部标志点的 x、y 和 z 坐标之间的差异在 0.17 毫米以内。使用跟踪软件，手动数字化和自动跟踪标志点之间的平均距离在 0.55 毫米以内。面部关键点的自动跟踪显示出令人满意的准确性，这将有助于对面部动画期间的动态运动进行分析。
