subpixel

A subpixel is an individual color element that forms part of a display’s pixel, most commonly red, green, and blue. In many display technologies, a pixel is composed of multiple subpixels, and the varying intensities of these subpixels combine to produce the full range of colors perceived by the viewer. Subpixels are the smallest addressable units of a display’s color output.

Subpixel rendering is a technique that uses the physical layout of subpixels to increase the apparent resolution and improve the sharpness of images and especially text. By aligning glyph edges to the subpixel grid and performing anti-aliasing at the subpixel level, the human eye perceives smoother contours and finer detail than would be possible by sampling only at the pixel level. This approach can yield crisper text on LCD and other fixed-subpixel displays, but relies on knowledge of the display’s subpixel arrangement and gamma behavior.

Subpixel geometry varies by panel technology. The most common arrangement is an RGB stripe, where each pixel contains a red, green, and blue subpixel in a horizontal sequence. Some displays use PenTile or other staggered layouts, which can affect rendering quality and may introduce color fringes if rendering assumes a different pattern.

Limitations and considerations include dependence on the display’s subpixel layout, potential artifacts under rotation or scaling, and the need for proper calibration of gamma and color management. Subpixel rendering is primarily a technique for font rendering and UI clarity rather than a universal solution across all image types.