Gregor Rozinaj, Renata Rybárová, Ivan Minárik, Juraj Kačur
Jozef Čepko
The module contains information about multimedia. At first basic knowledge concepts are introduced: analog and digital signals, digitization process and time and frequency representation. The other part describes signal processing, analog and digital technologies, filters and structure of a communication channel. Further there are described compression techniques of audio and video signals and multimedia technologies as speech synthesis, speech recognition and image recognition.
The main goal of the module is to introduce a student with the fundamental of signal processing, specifically multimedia processing. The student is clearly acquainted with the base principles of Fourier transformation, digital filters, linear systems, compression techniques and practical use of all knowledge in modern science.
Signal, transformation, channel, frequency, filter, audio, video, image
In the context of this book the term multimedia means an integration of text, picture and sound with purpose of conveying information. Each of the mentioned parts of information, or modalities, can be represented by several ways. Standard text, hypertext, tables or web pages can all be considered as text. To the pictures group belong static picture, dynamic picture, graphics, animation, video, etc. Specific parts of sound are music, speech, tones, sound signals, etc.
Multimedia is perceived by our senses. In addition to vision and hearing, which help us to “see and hear” the mentioned modalities, we sense the world also by other three senses: smell, taste and touch. Therefore we generally include signals that affect all five senses into the concept of multimedia. Multimedia communication often surrounds communication, which needs at least two senses; even though there are multimedia applications using just one sense.
By definition, multimedia application usually has a possibility of human interaction; it means it can be controlled by man. From this point of view classic TV does not belong to multimedia because it is not manageable.
A medium is defined as a way or a resource, which is used to present, sense, save or transfer information. Multimedium is a medium based on several modalities. Carrier of the media information is the signal.