Graphical images are composed
of 'pixels'. A pixel is a small square which has a specific colour.
An image is composed of thousands of these tiny squares layed
out in a grid.
An image may be built out of
10 pixels across and 20 pixels down. Each pixel has a unique
x and y co-ordinate. The x co-ordinate can range between 0 and
9, the y co-ordinate can range between 0 and 19. Every individual
pixel in the image can be refered to by its x,y co-ordinate.
The colour of each pixel is
built from three components. These three components are the primary
colours red, green and blue. Each of these components has a value
between 0 and 255, from this any colour can be built by mixing
them in the correct amounts. e.g
|
Red |
Green |
Blue |
Black |
0 |
0 |
0 |
White |
255 |
255 |
255 |
Green |
0 |
255 |
0 |
Yellow |
255 |
255 |
0 |