In [56] it is shown that computers are better than humans at solving all of the fundamental visual CAPTCHA problems, with the exception of the segmentation problem. a. What are the fundamental visual...

In [56] it is shown that computers are better than humans at solving all of the fundamental visual CAPTCHA problems, with the exception of the segmentation problem.

a. What are the fundamental visual CAPTCHA problems?

b. With the exception of the segmentation problem, how can computers solve each of these fundamental problems?

c. Intuitively, why is the segmentation problem more difficult for computers to solve?