In the figure at left, the two diagonal line segments appear to be offset from each other,
but they are actually part of the same line. In fact, the illusion is so strong that it
is often taken into account when designing logos and patterns. For example, although
the diagonal segments in the Union Jack (the flag of the United Kingdom, shown at right) are not
aligned, one pair of them appears as though they are.
Copyright © 2009 Shree Nayar. Computer Vision Laboratory,
Columbia University. Bigshot is a registered trademark.