![](/assets/images/picto-drapeau-france-3a76576a5d60a512053b4612ab58dae5.png)
2. Quantification
The signal is now sampled. The next stage in digitization is quantization. The bit rate is directly linked to this.
To quantize a signal, we need to define a quantization law and scale. The quantization scale has been set to 256 levels, i.e. 8 bits, and the law has been chosen to be linear. The choice of 8-bit words may seem obvious, given the components available and the habit of working on 8-bit, but it needs to be justified. For black and white, 7 bits of quantization suffice; for color – to which the eye is less sensitive – 6 bits of quantization suffice, hence the choice to work in bytes. This satisfies both luminance and chrominance constraints.
What's more, a better signal-to-noise ratio is obtained by choosing a logarithmic compression law, and the choice of this linear law may seem anomalous. But the video signal is already γ-corrected....
Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference
This article is included in
Signal processing and its applications
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Quantification
Bibliography
References
Recommendations
ITU-R BT 601-5 Oct. 1995 Digital television studio coding parameters for standard 4:3 (normalized) and 16:9 (widescreen) aspect ratios
ITU-R BT 656-4 Feb. 1998 Interface for digital component video signals in 525-line and 625-line television systems operating at the 4:2:2 level of Recommendation ITU-R BT 601 (Part A)
ITU-R BT 799-3 Feb. 1998 Interface for digital component...
Organizations
International Telecommunication Union - Radiocommunication Sector ITU-R http://www.itu.int/ITU-R/index-fr.html
European Broadcasting Union EBU
Builders and manufacturers
Thomson Broadcast http://www.thomsonbroadcast.com
Sonyhttp://bpgprod.sel.sony.com
Philips http://www.broadcast-philips.com
Barcohttp://www.barco.com
Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference