A video scaler is a device that converts the resolution of video signals, resulting in an output resolution that differs in size from the input. Though the output resolution can be made either higher or lower than the input signal, a video scaler is frequently used to improve the quality of video signals. For example, it can be used to enhance the lower resolution signal from a DVD player as it is transmitted to a higher resolution plasma television. This low- to high-resolution conversion is known as upconverting or upscaling.
Every video display contains a fixed number of pixels — the small dots that make up a display screen. A display’s quality — also known as resolution — typically is expressed in a figure that indicates the number of pixel per row multiplied by the number of rows, such as 1280 x 720 or 1024 x 768. Video signals and displays can have varying resolutions. A video scaler becomes necessary when the resolution of the input device is significantly different from the output device so that without the scaler the image quality would be distorted or compromised.
While video scalers come in numerous shapes and sizes, they typically are classified as either internal or external. Internal scalers are often found within devices such as televisions and computer screens; the video scalers in these devices resize incoming video signals and produce a detailed, high-quality image for viewers. External scalers most often take the shape of a hard case that resembles a cable box. This type of scaler can be useful with a home theater system or in a multimedia lecture hall where video signals from devices such as gaming systems or camcorders need to be converted for viewing on a large-scale display.
With a wide variety of models available at an array of price points, the external video scaler typically is an affordable option for most people. When purchasing a video scaler, it can be important for a shopper to note that no matter what resolution the scaler is capable of transmitting, a display’s quality cannot be improved beyond its highest inherent resolution. In other words, a video upscaler transmitting a signal at a resolution of 2048 x 1080 to a display with a resolution of 1280 x 720 can result in an image with a resolution no higher than 1280 x 720.