1. Digital data formats for representation of real objects Adolf Knoll National Library of the Czech Republic adolf.knoll@nkp.cz

2. Which objects to represent? Discrete chunks of reality perceivable by our senses:  Visual objects (still images)  Audio objects (sounds)  Video objects (moving images)  Abstract objects (evoked through text) Mixed objects, eg. audiovisual ones Digital data objects are created through direct transformation of these chunks of reality.

4. Digital audio and video Click on image to see video and on icon to listen to music

5. How are they created? Directly  Digital photo camera  Digital sound recording  Digital video recording  Digital text input Indirectly through analogue representation  Classical photograph  Analogue sound  Analogue video  Typewritten text Digitization produces computer file(s)

7. The analogue signal is digitized Analogue encoding  Continuous  For sound must be interpreted as well  Motion pictures are based on illusion made by moving discrete analogue images/frames Digital encoding  Discrete elements  Must be rendered into analogue  Motion pictures are based on illusion made by moving discrete digital images/frames Man can perceive and understand only analogue rendering of information. REAL WORLD vs. ENCODED WORLD