A (video) scaler is a device that changes (improves) the resolution of a signal. A typical use is the scaling or “upconverting” of a standard definition video signal to a high definition signal. Scalers are typically used in home theater and presentation environments as well as broadcast. Scalers can be stand-alone units or included in other products such as televisions or DVD players.
Buying Tip: You need to identify the signal inputs and outputs you need on both ends (Some pro scalers will allow you to go in with one format and come out another) as well as the output resolution formats and aspect ratios your display will support. More so than other devices, scalers have a direct impact on your picture quality. The quality of scalers can be night and day and prices range from a few hundred dollars to tens of thousands. Be wary of scalers built into other devices as many are low quality.