3. Pixels

As we mentioned earlier, computers can only handle 1s and 0s. They need absolute values, rather than a mishmash of different colours.

These values also need to be arranged in an organised manner, so that the computer can tell the position of every one.

The simplest way of doing this is with a grid, with a single value stored in one square of the grid.

So how do you do this with a photograph, which has millions of different colours?

The first step is mostly the same: make a grid.

We've overlaid the image below with a grid of lines. This divides it up into smaller sections.

The picture has effectively been divided into 11 horizontal elements (columns) and 8 elements vertically (rows). This is what happens when an image is digitised - it is divided up into many individual elements.