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Binary encoding of colours
The approach to encoding binary representations of colour is very similar to the approach we explored when looking at the encoding of alphanumeric values.
We begin by determining the total number of colours and colour shades we want to represent. With this value established we then decide on the bit-length required that will accomodate this number of variations. Finally, we assign a binary number to each representation.
Greyscale
We can start with a limited palette: greyscale. Here there is black and white
and number of interim shades of grey. The convention is to use an 8-bit number
which, given 2^8 = 256 provides 256 shade variations.
In decimal, 0 is equal to black (zero light intensity) and 255 is equal to white (full light intensity). Some examples of this (including binary and hex representations are below):
Colour encoding
A single 8-bit number is sufficient for 256 greyscale combinations but with
colour, the convention is to use three 8-bit numbers where each byte corresponds
to a value for red, green and blue (RGB). Thus the overall bit-length is 24
(2^3 + 2^3 + 2^3). Each value corresponds to a light intensity for the given
colour. Combined they are capable of representing all colours.
Some examples below
Red
Red is represented in RGB with all 8 red bits to set to 1 and the remaining 16 bits for the other two colours set to 0.
Yellow
Yellow is represented in RGB with both red and blue set to 1 and the remaining 8 green bits set to ):
