Quantization, involved in
image processing, is a
lossy compression technique achieved by compressing a range of values to a single quantum value. When the number of discrete symbols in a given stream is reduced, the stream becomes more compressible. For example, reducing the number of colors required to represent a digital
image makes it possible to reduce its file size. Specific applications include
DCT data quantization in
JPEG and
DWT data quantization in
JPEG 2000.