文件名称：《数字图象处理》（冈萨雷斯，第二版）习题答案
文件大小：1.72MB
文件格式：PDF
更新时间：2013-05-30 15:39:33
shuzituxiang
Problem 2.1 The diameter, x, of the retinal image corresponding to the dot is obtained from similar triangles, as shown in Fig. P2.1. That is, (d=2) 0:2 = (x=2) 0:014 which gives x = 0:07d. From the discussion in Section 2.1.1, and taking some liberties of interpretation, we can think of the fovea as a square sensor array having on the order of 337,000 elements, which translates into an array of size 580£ 580 elements. Assuming equal spacing between elements, this gives 580 elements and 579 spaces on a line 1.5 mm long. The size of each element and each space is then s = [(1:5mm)=1; 159] = 1:3£10¡6 m. If the size (on the fovea) of the imaged dot is less than the size of a single resolution element, we assume that the dot will be invisible to the eye. In other words, the eye will not detect a dot if its diameter, d, is such that 0:07(d) < 1:3 £ 10¡6 m, or d < 18:6 £ 10¡6 m.