Scalers typically are used to match a video signal to the resolution of a display, or to increase the perceived quality of a video image. When a standard television signal is displayed on a large, high resolution projection system, the image becomes over-expanded and the individual scan lines are visible. Scalers can eliminate these scan lines and create a clearer, smoother, and brighter image.

When used with digital displays, scalers take a standard analog signal, decode it, and use advanced digital signal processing technology to scale the image to the optimal or native resolution of the display. Furthermore, as scalers convert all signals to RGBHV, only a single video cable connection to the display is needed, resulting in simplified set-up and cable installations.

In the above diagram, video signals from a VCR, a DVD player, and other sources are running through a digital video scaler (DVS 406 AD). These inputs are then scaled for display by both a projector and plasma display.