Okay, so how do you actually do this?

You already know that pixels have red, green and

blue components which numerically represent the color.

Is there a big difference between a red value of 240 and a red value of 255?

They are numerically different, but if you look at them,

the two of them are pretty similar.

The fact that you can't easily tell the difference when you change

the numerical value slightly is the key to hiding data in an image.

You can store the hidden data in the least significant digits of the color value.

And not see much change in the resulting color.

The least significant digits are like the ones and

tens places in a three digit number.

So you could hide a 15 in 240 by changing 240 to 255.

To do this, you're going to need a bit of math.

Don't worry, it's just multiplication, division and addition.

You just have to put them together the right way.

To understand how to do this math, we're going to start with decimal.

The base ten number system you use everyday.

We'll explain the concepts in base ten.

Then learn about binary,

the base two number system that the computer uses to store numbers.