Bytes

Binary characters digits, "ones" and "zeros", are normally assembled into small standard-length groups just large enough to communicate a useful number. Such groups, normally consisting of eight bits, are known as bytes. One eight-bit byte can be used to represent an number in the range 0 - 255. The gaps in the binary numbers in the table below have been inserted purely to enhance readability.

 

BINARY NUMBERS AS EIGHT-BIT BYTES

Decimal

8-bit Binary

Decimal

8-bit Binary

1

0000 0001

128

1000 0000

2

0000 0010

140

1000 1100

3

0000 0011

160

1010 0000

4

0000 0100

180

1011 0100

50

0011 0010

200

1100 1000

60

0011 1100

220

1101 1100

70

0100 0110

240

1111 0000

80

0101 0000

253

1111 1101

90

0101 1010

254

1111 1110

100

0110 0100

255

1111 1111

 

In colour systems, such as the RGB colour model, primary colours are mixed in precisely-controlled proportions to achieve the large number of colours required to create an image. In the RGB system, the red, blue and green components are each allocated one eight-bit byte. This determines the mixture of primary colours required for each of the possible 16.7 million possible colour combinations. Each output of each sensor element, or pixel, therefore delivers three eight-bit bytes of information. This system, known as 24-bit colour, is illustrated in the example below which shows the data for a single orange pixel.