Lee Jang Yeol, Han Qiong, Trotman Carroll-Ann
Department of Orthodontics, Yonsei University, Seoul, Korea.
Angle Orthod. 2004 Oct;74(5):587-93. doi: 10.1043/0003-3219(2004)074<0587:TFIAAC>2.0.CO;2.
This study determined the accuracy of a camera system capable of recording three-dimensional facial images. A Rainbow 3D Camera Model 250 system (Genex Technologies Inc, Kensington, Md) was used to capture images of specific models: (1) a precalibrated precision model and (2) a mannequin model that served to simulate the human condition. To assess the accuracy of the camera system, repeated images of both models were recorded at two time points, one week apart. Repeated measurements of specific distances were recorded directly on the models and from each image. Means and standard deviations were calculated for all the repeated measurements at each time point. A two-tailed t-test was used to test for significant differences between (1) each distance measured directly on the precision model and the same distance measured on the images of the precision model, (2) each distance measured directly on the mannequin and the same distance measured on the images of the mannequin, and (3) the mean differences between the same distances measured at the two times. The findings showed that substantial image distortion occurred when images of sharp angles (90 degrees) were captured. Also, those images captured from the frontal perspective +/- 15 degrees were the most accurate.
本研究确定了一种能够记录三维面部图像的摄像系统的准确性。使用了一台Rainbow 3D Camera Model 250系统（Genex Technologies Inc，马里兰州肯辛顿）来捕捉特定模型的图像：（1）一个预先校准的精密模型和（2）一个用于模拟人体状况的人体模型。为了评估摄像系统的准确性，在两个时间点（相隔一周）对两个模型都进行了重复图像记录。在模型上以及从每张图像中直接记录特定距离的重复测量值。计算每个时间点所有重复测量值的均值和标准差。使用双尾t检验来检验以下各项之间的显著差异：（1）在精密模型上直接测量的每个距离与在精密模型图像上测量的相同距离；（2）在人体模型上直接测量的每个距离与在人体模型图像上测量的相同距离；（3）在两个时间测量的相同距离之间的平均差异。研究结果表明，当捕捉锐角（90度）图像时会出现明显的图像失真。此外，从正面视角±15度捕捉的那些图像最准确。
