Digital Video and HD, 2nd Edition

4

Quantization

A signal whose amplitude takes a range of continuous values is quantized by assigning to each of several (or several hundred or several thousand) intervals of amplitude a discrete, numbered level. In uniform quantization, the steps between levels have equal amplitude. Quantization discards signal information lying between quantizer levels. Quantizer performance is characterized by the extent of this loss. Figure 4.1 shows, on the left, the transfer function of a uniform quantizer.

Figure 4.1 A Quantizer transfer function is shown on the left. The usual 0 to 255 range of quantized R’G’B’ components in computing is sketched on the ...