Anti-aliasing
A rendering technique that smooths jagged edges (staircase artifacts) on diagonal lines and curves by blending intermediate colors at boundaries.
Anti-aliasing is a technique used to reduce the visual artifacts known as aliasing or "jaggies" that appear along diagonal lines and curves in raster images. Because pixel grids cannot perfectly represent non-axis-aligned edges, anti-aliasing places intermediate-colored pixels along boundaries to create the illusion of smoothness to the human eye.
- Supersampling (SSAA): Renders the scene at a higher resolution than the display, then downsamples by averaging multiple samples per output pixel. Produces excellent quality but demands significant computational resources
- Multisampling (MSAA): Applies multiple samples only at polygon edges rather than every pixel. Widely used in 3D gaming as it offers a favorable balance between visual quality and performance cost
- Subpixel rendering: Exploits the RGB subpixel structure of LCD panels to increase the apparent resolution of text. Windows ClearType and macOS font rendering both employ this technique
In web development, CSS properties like -webkit-font-smoothing and the Canvas API's imageSmoothingEnabled control anti-aliasing behavior. Image editors allow toggling anti-aliasing on selection edges and brush strokes. Some artistic styles, such as pixel art, intentionally disable anti-aliasing to preserve crisp, blocky edges as a deliberate aesthetic choice.