Perspective and perception: vision and touch

图片是我们最有效的信息交流方式之一。但它们的用途仍然是神秘的，它们的潜力仍然是未知的。我们如何感知和呈现3D空间？值得注意的是，盲人使用透视法来解决这个问题，而不仅仅是视力正常的人。但怎么做呢？视觉和触觉都必须有一种方式来回应透视图片的特征。在估计中距离地面物体的形状时，视觉通常是正确的。但是，自从透视几何学首次被发明以来，人们就清楚地看到，知觉所能处理的透视图像有着惊人的局限性。地板上远处的瓷砖看起来很近。图片侧面的瓷砖看起来非常拉伸;也就是说，在完美透视图片的边缘，形式看起来扭曲，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于知觉低估了透视缩短造成的。同样的效果也可能发生在触觉和视觉上，因为盲人和真正的盲人会指向一排渐行渐远的物体。

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.