Perspective and perception: vision and touch

图片是我们交流信息最有效的方式之一。但它们的用途仍然是个谜，它们的潜力仍然未知。我们如何感知和表现3D空间？值得注意的是，盲人使用视角来解决这个问题，而不仅仅是视力正常的人。但如何做到呢？视觉和触觉都必须有一种方式来响应透视图片的特征。在估计坐在地面上的中等距离物体的形状时，视觉往往是正确的。但自从透视几何学首次被设计以来，很明显，感知所能处理的透视图像存在着惊人的局限性。地板上远处的瓷砖看起来可能会很短。图片边上的瓷砖可能看起来非常拉伸；也就是说，在完美透视图片的边缘，形状看起来扭曲、高度膨胀。这就是为什么仅供日常使用的相机包含窄角镜头，而不是显示边缘失真的广角镜头。这些影响可能都是由知觉低估了缩略造成的。同样的影响可能发生在触觉上，也可能发生在视觉上，因为视力蒙住眼睛和真正失明的人会指着一排向远处后退的物体。

Pictures are one of our most effective ways to communicate information. But their uses remain mysterious and their potential is still unknown. How do we perceive and represent 3D space? Remarkably, blind people use perspective to solve this problem, not just the sighted. But how? Both vision and touch must have a way of responding to the features of perspective pictures. Vision is often correct in estimating the shape of middle-distance objects sitting on the ground. But since the geometry of perspective was first devised it has been obvious that there are striking limits to the perspective pictures that perception can handle. Distant tiles on a floor can look stubby. Tiles on the sides of pictures can look very stretched; that is, on the margins of perfect perspective pictures, forms appear distorted, highly distended. This is why cameras for everyday only use contain narrow-angle lenses, not wide-angle lenses that reveal the marginal distortions. These effects may all be caused by perception's underestimation of foreshortening. The same effects may occur in touch, as well as vision, as sighted-blindfolded and truly blind people point to a row of objects receding into the distance.