### Today's topic: Digital Images. Part 1. Introduction to Grayscale.

Okay, first things first. Here is a single number, a *scalar*: 5

Here is a list of numbers: 5 6 7 8

Here's another list, or alternatively a *string* of numbers: 3 1 0 0 3

So what if we have a *string* of *strings*, or a list with both rows and columns, just like you would find on an Excel Spreadsheet? Well, that would be a *matrix*.

We'll put some **[** brackets **]** around them for some neat structure. Here's an example:

*Well, guess what?! We can show this matrix as an image! *

Black is 0 and white is 255, with shades of gray in between. Alternatively, we can divide this matrix by 255 and have white represented by 1, with gray values being decimals between 0 and 1. Some people prefer this way of doing things. Such a matrix (rounded to four decimal places) would look like this:

And that's all for now, folks! Hope you enjoyed this quick lesson.

Up next: **Color images. **