Web-Site Explains Image Quality Improving Techs

FSAA and AF in Details

by Yaroslav Lyssenko

[ 07/07/2005 | 09:43 PM ]

Bit-tech.net has posted an article wish explains some standard modern graphics cards features. The Full Scene Anti-Aliasing (FSAA) as well as Anisotropic Filtering (AF) technologies implemented in all of the latest graphics cards are aimed to enhance image quality in 3D applications. The article includes some analysis and picture quality comparison made with and without FSAA and AF enabling.

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“If you can’t increase resolution, you turn to anti-aliasing which, as the name might suggest, is a technique designed to reduce the appearance of jagged lines. Anti-aliasing blends the edges of shapes using color to make them less harsh, effectively fooling the eye into thinking the line is smoother than it is. Of course, this blending reduces the sharpness of the line and over-blending can make it blurry. Anti-aliasing techniques aim to keep blurring to a minimum whilst reducing the aliasing that can be apparent,” writes Bit-tech.net.

While FSAA is aimed at reducing the appearance of jagged lines, anisotropic filtering is designed to insure better quality of the whole scene and improve the clarity of the textures. 

“To understand this technique, we must understand how textures are applied to a 3D scene on your screen. Textures are the images, the details if you like, that sit on top of bare lines. A scene rendered without textures looks blocky and simple, whereas a scene with textures on immediately adds realism. As a 3D scene stretches into the distance, less detail is required as the objects become further away. Rendering textures that are far away at a lesser detail than those that are closer to the player means that graphics cards can give better performance. These lower-quality distance textures are called mipmaps. However, what can be evident are the points at which the different levels of texturing change. Often, changes between mipmap levels are all too evident on the screen. Textures are therefore filtered to make the transitions between different levels smoother. The higher the level of anisotropic filtering, the better image quality is achieved for mipmap transitions,” writes the author.

• Bit-tech.net: Aliasing and Filtering Explained.