Anti-Aliased Text
   
Home
 
Books
 
File Formats
 
Glossary
 
Software
 
Tutorials
     
GraphicsAcademy.com  >  Glossary  >  Anti-Aliased Text

Anti-Aliased Text

Anti-aliasing is a method of drawing text or pictures which smooths edges, and avoids jagged edges ("jaggies").

In this article we'll discuss anti-aliasing as applied to drawing text.

Imagine that we wish to place a character glyph from an outline font on a bitmap. Looking at it closely (enlarging so that you can see the individual pixels), it might look something like this example:

Overlaying a Glyph on a Pixel Grid

There is an obvious problem, if you look closely at the above diagram. Namely, when we try to convert the glyph to a bitmap ("rasterise"), we can only have a single color for each individual pixel, but some of the cells in the pixel grid contain both red and white.

So how do we address this problem?

A simple solution (not anti-aliased) would be to look at each pixel cell:
  • If the pixel cell contains nothing but white, we make the pixel white.

  • If the pixel cell contains nothing but red, we make the pixel red.

  • If the pixel cell contains both red and white, we can choose to make the pixel red or white. For example, we might choose whichever color covers a larger proportion of the cell.
Here's an example of how this might look:

The Glyph Rasterised
Not Anti-Aliased

That isn't bad, but as you can see, it does look a little bit jagged (see "Jaggies").

This problem can be addressed by modifying our method of rasterising the glyph. This new method (anti-aliasing) works:
  • As before: If the pixel cell contains nothing but white, we make the pixel white.

  • As before: If the pixel cell contains nothing but red, we make the pixel red.

  • However: If the pixel cell contains both red and white, we make the pixel an intermediate color between red or white (a lighter shade of red).

    • The more white in the pixel cell, the lighter (more whitish) we make the final pixel color.

    • The more red in the pixel cell, the redder we make the final pixel color.
Here is the result it produces:

The Glyph Rasterised
Anti-Aliased

This time, it doesn't look jagged, but it does (to some eyes at least), look a little blurred. This difference will become clearer when we compare the images at their final sizes.

Finally, here is a comparison, at actual size, of text which has been anti-aliased, and text which has not been. (I have also included a comparison between two blocks of black and white text - in this case, the anti-aliasing is done using shades of gray rather than red).

Not Anti-Aliased Anti-Aliased
 

 		  

 
 

 		  

 



Related Pages on this site:
Related Books:
  • Computer Graphics Dictionary (Advances in Computer Graphics and Game Development Series)
     
    Computer Graphics Dictionary (Advances in Computer Graphics and Game Development Series)
         		  
    Charles River Media
    Hardcover (460 pages)

    Product Description:
    The popularity of special effects movies and the video game industry has introduced thousands of new terms, techniques, and software applications to both the computing professional and the general user. Unfortunately, these graphics creations represent a convergence of expertise from several different subject areas, resulting in a lack of familiarity with many terms. This unique dictionary includes over 4,000 definitions and illustrations from the computer graphics world, including those from digital filmmaking, animation, programming, mathematics, holography, photorealism, lighting, character creation, game development, modeling, and more.

    List Price: $49.95
    Lowest New Price: $4.00
    Lowest Used Price: $0.04
    Usually ships in 24 hours
    (As of 13:18 Pacific 21 May 2008 More Info)

    Buy It Now
     


  • Graphic Design Speak: A Visual Dictionary for Clients and Designers
     
    Graphic Design Speak: A Visual Dictionary for Clients and Designers
         		  
    By Anistatia Miller

    Rockport Publishers
    Hardcover (160 pages)

    Book Description:
    What does a client or art director really mean when they say "I want a clean look" or "The design should be bold"? Graphic Design Speak offers the answers in an easy-to-follow format that both clients and designers can use as points of reference in design briefs or strategy meetings. This book is an essential tool for any designer seeking to gain a better knowledge of the wants and needs of their clients.

    --Over 200 color projects showing specific design solutions to answer client demands

    --An international gathering of designers, studios, and ad agencies

    --Quotes, tips, and anecdotes from both designers and clients

    List Price: $40.00
    Lowest Used Price: $10.00
    (As of 13:18 Pacific 21 May 2008 More Info)

    Buy It Now
     


Related Software:
  • FontTwister
    FontTwister is the fastest and easiest way to create dazzling text effects. FontTwister comes with an impressive selection of templates for graphic styles, color gradients, textures, shapes, letter edges, 3-D bevels, shadows, buttons and frames. Simple intuitive controls let you interactively real-time view and select your desired effect. You can re-edit text and effects at any time. The effect generator creates unlimited variations of amazing text effects.


    Use high impact, anti-aliased text for logos, 2D and 3D headings in letters, presentations, flyers, invitations, cards, faxes, posters, web graphics, labels, banners, buttons, covers. FontTwister supports several popular image formats (.bmp, .jpg, .png, .tif, .wmf).

Related Web Sites:

 		    
 
Privacy     Terms Of Use

Copyright © 2005-2008, Answers 2000 Limited

With any business, it is up to the individual owner of said business to ensure the success of the business. You may make more or less than any sample figures or results that might be quoted on our web sites or other publications. All business involves risk, and many businesses do not succeed. Further, Answers 2000 Limited does NOT represent that any particular individual or business is typical, or that any results or experiences achieved by any particular individual/business is necessarily typical.

In Association With Amazon.com
All trademarks are property of their respective owners.
All third party content and adverts are copyright of their respective owners.

Some graphics on our web sites are Copyright (C) 1997-2000 Hemera Technologies Inc., and used under license. All such pictures are provided for viewing purposes only and are not to be saved or downloaded. All such pictures of recognizable individuals are models and used for illustrative purposes only, and not meant to imply any association or endorsement of said individual with any product or service.