A video scaler is a device for converting video signals from one size or resolution to another: usually "upscaling" or "upconverting" a video signal from a low resolution (e.g. standard definition) to one of higher resolution (e.g. high definition television).
Video scaler devices can be found embedded in:
Video scalers can also be a completely separate box, often providing simple video switching capabilities. These units are commonly found as part of home theatre or projected presentation systems. Home theatre uses might include converting a standard definition DVD or video game signal into high-definition for display on an LED, LCD or plasma television while obtaining the best image quality possible. Scalers can also be found in schools, lecture theatres and modern churches, where numerous video sources (e.g. DVD video, live camera feeds, DVI/VGA output from a computer) need to be switched between, while the highest possible resolution is maintained.
Video scalers are primarily a digital device, however they can be combined with an analog-to-digital converter (ADC, or digitizer) and a digital-to-analog converter (DAC) to support analog inputs and outputs. One upscaling process that has gotten a lot of attention is the IMAX DMR.
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The "native resolution" of a display is how many physical pixels make up each row and column of the visible area on the display's output surface. There are many different video signals in use which are not the same resolution (neither are all of the displays), thus some form of resolution adaptation (video scaling) is required to properly frame a video signal to a display device. For example, within the United States, there are NTSC, ATSC, and VESA video standards each with several different resolution video formats.
Video scalers are often combined with other video processing devices or algorithms to create a video processor that improves the apparent definition of video signals. These other devices may include the ability for:
These can either be in chip form, or as a stand alone unit to be placed between a source device (like a DVD player or set-top-box) and a display with less-capable processing. The most widely recognized video processor companies in the market as of June 2007 are:
All of these companies' chips are in devices ranging from DVD upconverting players (for Standard Definition) to HD DVD/Blu-Ray Disc players and set-top boxes, to displays like plasmas, DLP (both front and rear projection), LCD (both flat-panels and projectors), and LCOS/”SXRD”. Their chips are also becoming more available in stand alone devices (see "External links" below for links to a few of these).