Tutorial on Anti-Aliasing(AAing)

DustyPorViva · #1 11-16-2003, 09:58 AM

Ok, this is going to be mainly directed to "pure-pixelists" because, well, there is a tool to do it with programs.

So, let us carry on.

Anti-Aliasing, now going to be referred to as AAing, is used to smooth out two contrasting colors, and make them easy on the eyes.

Step one:

I've made an example of something that is in desperate need of AA.

Look at how harsh that black looks against that easy white. It almost hurts to see those rough corners.

Step two:

Maybe some people, that saw a picture that used AA, will try it, but not really understand the logic of it, will try it.
They might end up with this.

Hmm, you gave it a 50% mixed outline. Nah, that's not working.
It doesn't make it any smoother, just extends the harshness one more pixel in width.

Step three:

Let's get onto how we actually do AAing.
You'll want to get some color selection, that ranges in a mix of the two colors. In this case, grey will be fitting.
Now that you know what your going to be using, lets get on to using it.
The main things that give that rough edge are those protruding edges. That is your main aim here. Find them and take that mid-color, and stretch it from the darker color, to the lighter. BUT, do not bring it to the edge. leave maybe one pixel if it's short, if it's a long line, just draw it half-way.

Here is how the corners should look:

And the image as a whole:

If your limiting color count, and only want to use 1 color for the AAing, make sure you get a 50% mixed color between the two.

Otherwise...

You can choose a gradient of colors between the two.
75%, 50%, 25% and so on.

This always helps it look smoother.

And here is how you go about doing that:

Take the old AAing you did, with the single 50% color, and change that to the lesser color your using now.
In this example I used 25% grey. Now, take the next color you plan on using(darker) and perform an interior AA of the previous AAing and darker color.

This gives an even smoother transition.

I guess that concludes this tutorial. I can't get into the technical spefications of AAing, such as gamma, because I am unaware of them. But even without knowing that, you can still pull it off with an artist's eye.

Any questions?
I hope this helps. I know AAing really should be used more often.

haunter · #2 11-16-2003, 10:08 AM

You should put a comparison of before, and after at the end of the tutorial

Kramer · #3 11-16-2003, 10:09 AM

It's a nice tutorial, but try that with a transparent background and put it over grass tiles and it just looks worse. Good for single images though.

DustyPorViva · #4 11-16-2003, 10:12 AM

I was going to do that, but didn't think it was necessary.

But here it is anyways:

DustyPorViva · #5 11-16-2003, 10:14 AM

Quote:

Originally posted by Kramer
It's a nice tutorial, but try that with a transparent background and put it over grass tiles and it just looks worse. Good for single images though.

Well that's not what this is for.
This is directed at two colors, that which won't change, and you are capable of calculating the difference between the two colors.

This isn't meant for semi-transparency or alpha-blending.

Kramer · #6 11-16-2003, 10:16 AM

Quote:

Originally posted by DustyPorViva

Well that's not what this is for.
This is directed at two colors, that which won't change, and you are capable of calculating the difference between the two colors.

This isn't meant for semi-transparency or alpha-blending.

I figured, watch your double posts.

VeX_RaT_Boy · #7 11-16-2003, 09:14 PM

Quote:

Originally posted by Kramer

watch your double posts.

That is hard when theres 1 min between the post. The second post got posted while he wrote a reply to the first.

Anyways, nice tutorial..

Loriel · #8 11-17-2003, 02:01 AM

You should stop teaching people to use GIF.

Here is my attempt, it looks smoother imho but I cheated

Also it is about 1/5 the file size of your original one bit image.

DustyPorViva · #9 11-17-2003, 02:20 AM

I'm not teaching anyone to use GIF. And there is nothing wrong with it in this instance. No need to debate it though.

Anyways, your's seems okay, but it's lacking the lighter transition color. Also, you should try and not fill the one pixel corners, unless it's with a light color, not dark.

marcoR · #10 11-17-2003, 04:21 AM

I very much appricate the tutorial, and it should be added to Kaimetsu's bunch-o-tutorials in the main graphics forum

It gives the information needed =D good job! Perhaps I should do one ¬_¬