EE4209/EE5809 Quantization

EE4209/EE5809 Quantization

1. samples must be taken at discrete points in time or space, but how each sample is represented in a computer.

2. Let n be the number of bits used to quantize a digital sample. Then, the maximum number of different values that can be represented, m, is m = 2**n

3. For digital audio,each sample represents the amplitude of sound wave at a discrete point in time. Common sample sizes are 8 or 16 bits.

Stereo CD-quality digital audio uses 16 bits per sample in each of the 2 stereo channels, for a total of 32 bits per sample.

4. Sample size affect how precisely the value of a sample can be represented.

5. In digital sound, sample size affects how much you have to round off the amplitude of the wave when it is sampled at various points in time.

6. A sample must be rounded to the closet discrete level. The difference between its actual value and its rounded value is the quantization error.

7. The amount of error implicit in a chosen bit depth can be measured in terms of the signal-to-noise ratio (SNR )