What is Anti Aliasing and What Does It Do?

Anti-Aliasing is a term used lots when selling graphics cards, but what exactly is Anti-Aliasing? They look deeper in to the reasoning behind Anti-Aliasing & why they require it in the first place. There is varying types of anti-aliasing producing different results & different levels of performance hit.

 

More about Anti-Aliasing

AA is a process of fooling the eye that a jagged edge is smooth. Anti-Aliasing is often referred in games & on graphics cards. In games the chance to smooth edges of the images goes a long way to making a realistic 3D picture on the screen. Keep in mind though that AA does not actually smooth any edges of images it merely fools the eye. Like plenty of things they are only designed to be lovely. In the event you cannot tell the difference then that is fine. Let’s take a glance at the example below to demonstrate the effects of AA.

 

 

The letter on the left is a blown up letter "a" with no anti-aliasing. The letter on the right has had anti-aliasing applied to it. In this blown up form it looks like it’s fundamentally blurred but in the event that they reduce the size down to a more standard size you might even see the difference.

Now look closely at the letters. You can still tell that the letter of the left is jagged but the letter on the right looks a lot smoother & less blurry than the example above. Keep in mind I have only shrunk the picture down back to normal size & have not altered anything else to the picture at all. So as you can see, AA brings a way more pleasing picture to the eye. Something like what comes out of a high class printer than what you can be used to seeing when on a computer screen.

What are Jagged Edges?

Jagged edges are cause by limitations in a computer screen; whether that is a CRT or LCD screen it’s all the same. Monitors are capable of producing ideal straight lines either horizontally or vertically, but when it comes to diagonal lines of any angle your monitor is unable to producing a line without some jagged edge. This is because your screen is made up of pixels in a grid formation. When you draw a diagonal line on a computer screen it is to cross several grid lines, because pixels generate blocks of color diagonal lines displace these blocks slightly causing jagged edges, Check out the following example to see what happens on your screen.

 This is a graphic on a grid of how they would draw a diagonal line on a grid. As you can to receive a straight line they must cross over the grid lines. Here is a graphic of how a computer would draw the same line.

As you can see the line is jagged. This is because the grid squares are pixels & half a pixel cannot be color & half the other. The pixel is red or white in this case. And this is how the line looks like when AA is activated:

Newer monitors are combating the issue themselves by decreasing the dot pitch. Dot pitch is the space between pixels. The closer the pixels the less jagged to lines appear. However while this can decrease the effects it cannot solve them.

Continued at part 2, stay tuned!