Burton A M, Bruce V, Dench N
Department of Psychology, University of Nottingham, UK.
Perception. 1993;22(2):153-76. doi: 10.1068/p220153.
Human subjects are able to identify the sex of faces with very high accuracy. Using photographs of adults in which hair was concealed by a swimming cap, subjects performed with 96% accuracy. Previous work has identified a number of dimensions on which the faces of men and women differ. An attempt to combine these dimensions into a single function to classify male and female faces reliably is described. Photographs were taken of 91 male and 88 female faces in full face and profile. These were measured in several ways: (i) simple distances between key points in the pictures; (ii) ratios and angles formed between key points in the pictures; (iii) three-dimensional (3-D) distances derived by combination of full-face and profile photographs. Discriminant function analysis showed that the best discriminators were derived from simple distance measurements in the full face (85% accuracy with 12 variables) and 3-D distances (85% accuracy with 6 variables). Combining measures taken from the picture plane with those derived in 3-D produced a discriminator approaching human performance (94% accuracy with 16 variables). Performance of the discriminant function was compared with that of human perceivers and found to be correlated, but far from perfectly. The difficulty of deriving a reliable function to distinguish between the sexes is discussed with reference to the development of automatic face-processing programs in machine vision. It is argued that such systems will need to incorporate an understanding of the stimuli if they are to be effective.
人类受试者能够非常准确地识别面部的性别。使用成年人的照片，照片中头发被泳帽遮住，受试者的识别准确率达到了96%。先前的研究已经确定了男性和女性面部存在差异的多个维度。本文描述了一种将这些维度组合成一个单一函数以可靠地对面部进行性别分类的尝试。拍摄了91张男性面部和88张女性面部的正面和侧面照片。这些照片通过几种方式进行测量：（i）图片中关键点之间的简单距离；（ii）图片中关键点之间形成的比例和角度；（iii）通过正面和侧面照片组合得出的三维（3-D）距离。判别函数分析表明，最佳判别指标来自正面的简单距离测量（12个变量时准确率为85%）和三维距离（6个变量时准确率为85%）。将从图像平面获取的测量值与三维测量值相结合，得到了一个接近人类表现的判别指标（16个变量时准确率为94%）。将判别函数的表现与人类感知者的表现进行了比较，发现两者存在相关性，但远非完美相关。文中结合机器视觉中自动面部处理程序的发展，讨论了推导可靠的性别区分函数的困难。有人认为，这样的系统如果要有效，就需要纳入对刺激的理解。
