Digitization
- Sampling
- Quantization
- Encoding
Sampling
- Nyquist theorem: The sampling frequency must be at least twice the highest frequency present for a signal to be reconstructed from a sampled version. Nyquist frequency: $f_s \ge 2\cdot f_{max}$
Quantization

Bit Rate
- Bit Rate (bits/second) = Sampling rate (Hz) x Quantization per sample (bits)
Image
- RGB image has 3 channels (red, green, blue)
- Bit depth(位深):每个通道的位数
- 典型:8-bit、16-bit、32-bit float(都是 per channel)
- Bits per pixel(bpp,像素总位数 / 也常被叫“color depth”):位深 × 通道数
- 例如:8-bit × 3 通道(BGR)= 24 bpp