Page 238 - Introduction to AI Robotics

6.6 Computer Vision
Blue Cyan 221
(0,0,255) (0,255,255)

Magenta White
(255,0,255) (255,255,255)

Black Green
(0,0,0) (0,255,0)

Red Yellow
(255,0,0) (255,255,0)

Figure 6.11 RGB color cube.

be operating in an environment where the only visible colors will not have
an ambiguity.
24-bit color is usually sufficient for robotics. For other applications of com-
puter vision such as medical imaging, weather forecasting, or military re-
conaissance, an 8 bit resolution is often insufficient. Those applications may
use 10 bits for each color plane. Since 10 bits do not fall on a byte boundary,
it can be awkward to program algorithms for representing and manipulat-
ing this kind of image. Companies such as Pixar make special computers for
these applications.
In programming terms, 24-bit color image is often declared in computer
programs in two ways:

1. Interleaved. Interleaved means the colors are stored together, RGB RGB
RGB ..., and it is the more common representation. The order is almost
always red, green, then blue, although there may be framegrabbers which
do not follow that convention. Below is a code fragment where the color
is displayed for a pixel at location row, col.

#define RED 0
#define GREEN 1
#define BLUE 2