Figure 21 shows the
sign regions detected in this image. The interstate symbol in the centermost
sign was surrounded by green sign regions and therefore detected. The sign partially
visible on the right was not detected due to bleeding problems in the image
growing routines. In this particular case, the seed pixel chosen to grow that
sign region happened to have an intermediate color as a result of averaging
between the white sign border and the foliage behind the sign. This caused fragmentation
of the sign region, and the resulting areas were smaller than the size threshold.
The remaining detection modules did not produce any false alarms for this image.