SUBSAMPLING

(n.) A mathematical reduction of the data in a data set to a subset of its original components. For example, if you have captured a 512-by-512 image, but want to encode it at a resolution of 256-by-256, you can subsample the data before encoding it by discarding every other pixel in both and x and y directions. On systems that work with YUV data, you can also subsample the U and V chrominance information so that each pixel has a unique luminance value, but shares chrominance information with one or more nearby pixels. See also data compression .