Design Nomenclature / Digital Model Making
Anti-aliasing
Also called AA, antialiasing, edge smoothing, grayscale AA
Reconstructing a signal the sample grid cannot represent, by weighting each pixel with the fraction of it a shape covers instead of a hard in-or-out test. It does not blur the edge; it estimates the correct value for a sample straddling one. Without it, aliasing shows up as stair-steps, shimmer, and moiré.
In practice
For type it is a family, not a setting — grayscale, subpixel, hinted or not — and which one runs is decided by the operating system and the rasterizer, not by you.
Not to be confused with
- Subpixel RenderingTreating an LCD's red, green, and blue stripes as three independent samples, tripling horizontal resolution for a shape whose position is known relative to them. It depends on a fixed, known subpixel layout in a known orientation — rotate the panel, change to a non-stripe arrangement, or composite the buffer, and it degrades into colour fringing.
- RasterAn image stored as a grid of samples. It has no notion of what it depicts — a letterform in a raster is not a letter, it is the pixels a letter left behind. Scaling means resampling, and resampling invents data. Cost is fixed by dimensions regardless of content, which is why photographs are raster.