Subpixel Rendering

Subpixel rendering increases the apparent resolution of color LCD screens. The technology addresses the individual elements of each pixel, leading to improved legibility of characters and shapes displayed on-screen.

Subpixel rendering effectively triples the resolution of the LCD screen in the horizontal direction, allowing for improved character shapes and spacing. Bitmap-like edges, also know as “jaggies,” are virtually eliminated as character shapes are smoothed and refined. Subpixel rendering ensures a consistent look throughout the weight of any font.

Which Devices Benefit From Subpixel Rendering?
Subpixel rendering is ideal for cell phones, e-books, PDAs, digital cameras, camcorders or any type of device using a color LCD that needs to display small, highly-legible text. The technology also improves character legibility on laptop computer monitors and vertical stripe television screens. Subpixel rendering performs best on medium to high-resolution devices.

How Does Subpixel Rendering Work?
Subpixel rendering takes advantage of vertical LCD screen geometry, wherein each pixel is composed of three individually colored subpixels – red, green and blue. At normal viewing distances of 20 inches or more, each pixel on a 15-inch LCD screen of 1024x768 pixels is perceived by the human visual system as white. The human eye cannot discern the individual subpixels from such distances. It is well documented that the human eye is dramatically more sensitive to brightness than either hue (tint, color) or saturation at small sizes. Also, the human visual system will intensify brightness gradients above a certain threshold.

Subpixel rendering is based on the manipulation of each subpixel rather than the whole pixel. By varying the luminance of the adjacent subpixels, the eye can be tricked into perceiving these colored subpixels as shades of gray, so that the eye recognizes this unusual colored image as a smoother black character. The technology relies on some properties of the human visual system to improve character shapes and character spacing to achieve better apparent resolution.

Benefits Include:

increased readability of type on LCD screens

improved character spacing and shapes

improved progression of character weight

increased ability to use small text sizes, allowing more information to be displayed