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Computer science from A to Z

N is for Numerical (Digital)

© INRIA Sophie Auvin - N comme Numérique

Camcorders, personal music players, telephones, computers... digital devices do not easily digest the incredibly nuanced, constantly changing information from the world around us.

They can only record, process or display digitised data, which only take into account a certain number of clearly determined values.

They have no problem ingesting text, as each character corresponds to a distinct value.

But how can they assimilate an image? The image is broken down into tiny squares called pixels. Each pixel has a uniform colour, selected from a palette of a few hundred or several million.

Music is processed in the same way: it is broken down into tiny time intervals in which the sound intensity, which is considered to be constant, is coded by a whole number.

Once digitised, all data are interchangeable, and the different devices converge: a computer becomes a telephone, a telephone can be used to shoot videos and a television can be used to surf the Internet!

Did you know...?

© INRIA / Sophie Chauvin - Numérique

The digitised value of a piece of information is often an approximation of its real value.

The more accurate this approximation, the more storage space is required to record the information.

Keywords: Computer science from A to Z Science awareness