Glossary A–ZLetter S
Scaler
A scaler is the electronics that converts an incoming video signal to a screen's actual resolution.
Every screen has a built-in scaler. It also exists as a separate device or as part of video processors for video walls and LED walls.
If a player sends Full HD to a 4K screen, the scaler upscales the picture to four times the number of pixels. Conversely, it downscales signals that are larger than the panel. For LED walls with unusual resolutions, such as a very wide band, an external scaler adapts the player's signal to the grid of the wall. Some scalers also convert the refresh rate or the aspect ratio.
Every conversion can cost sharpness, make text look soft and add a small delay. Wrong settings cut off the edges of the picture or distort it. The best quality is achieved when content and player output are already at the screen's resolution, so that the scaler has nothing to do. Operators should match the player's output resolution to the screen's resolution and, if the edges are cut off, switch off overscan in the screen menu.