Файл: Modern multimedia technologies.pdf

1) Introduction

Multimedia is a modern computer information technology that allows you to combine text, sound, video, graphics, and animation(animation) in a computer system. Multimedia is the sum of technologies that allow a computer to enter, process, store, transmit, and display (output) data types such as text, graphics, animation, digitized still images, video, sound, and speech.

30 years ago, multimedia was limited to the "Consul" typewriter, which not only typed but could also attract the attention of a sleeping operator with a melodious crackle. A little later, computers were reduced to household appliances, which allowed them to be assembled in garages and rooms. The invasion of Amateurs gave a new impetus to the development of multimedia (computer horoscope in 1980, which using a speaker and a programmable timer synthesized vague verbal threats for each day, and even moved the stars on the screen (the beginnings of animation)). Around this time, the term multimedia itself appeared. Most likely, it served as a screen that shielded the laboratory from the eyes of the uninitiated.

A critical mass of technologies is accumulating. Blasters, CD ROM and other fruits of evolution appear, the Internet, WWW, and microelectronics appear. Humanity is experiencing an information revolution. And now we are witnessing how the public need for means of transmitting and displaying information is bringing to life a new technology, for lack of a more correct term, calling it multimedia. Today, this concept can completely replace the computer in almost any context.

The emergence of multimedia systems is certainly making revolutionary changes in such areas as education, computer training, in many areas of professional activity, science, art, computer games, etc.

The appearance of multimedia systems is prepared both with the requirements of practice and with the development of theory. However, the sharp leap in this direction that has occurred in this direction over the past few years is primarily due to the development of technical and system tools. This is the progress in the development of personal computers: dramatically increased memory capacity, performance, graphics capabilities, characteristics of external memory, and advances in video technology, laser disks — analog and CD-ROM, as well as their mass implementation. The development of methods for fast and efficient data compression / scanning also played an important role.

A modern multimedia PC in full “armament” resembles a home stereo Hi-Fi complex combined with a display TV. It is equipped with active stereo speakers, a microphone and a CD–ROM optical disc drive (CD–Compact Disc, CD — ROM; ROM–Read only Memory, read — only memory). In addition, a new device for PC is hidden inside the computer-an audio adapter that allows you to switch to listening to pure stereo sounds through speakers with built-in amplifiers.Multimedia technologies are one of the most promising and popular areas of computer science. They aim to create a product containing " collections of images, texts, and data accompanied by sound, video, animation, and other visual effects (Simulation), including an interactive interface and other control mechanisms." This definition was formulated in 1988 by the largest European Commission dealing with the problems of introduction and use of new technologies. The concept of memory organization "MEMEX", proposed in 1945 by the American scientist Vanniver Bush, is considered an ideological prerequisite for the emergence of multimedia technology. It provided for the search for information in accordance with its semantic content, and not by formal signs (by the order of numbers, indexes, or alphabets, etc.). This idea found its expression and computer implementation first in the form of a hypertext system (a system for working with combinations of text materials), and then hypermedia (a system that works with a combination of graphics, sound, video, and animation), and finally in multimedia, combining both these systems.However, the surge of interest in the late 80's in the application of multimedia technology in the humanitarian fields (and, in particular, in the, in historical and cultural terms) is undoubtedly associated with the name of an outstanding American computer scientist-businessman bill gates, who owns the idea of creating and successfully implementing a multimedia (commercial) product based on a service (!) Museum inventory database using all possible "environments": images, sound, animation, hypertext system ("National Art Gallery. London")

This product has accumulated three main principles of multimedia:

Representation of information using a combination of multiple human-perceived environments;

Multiple storylines in the product content (including those that are built by the user based on "free search" within the information offered in the product content);

Artistic design of the interface and navigation tools.

The following multimedia features are an undoubted advantage and feature of the technology, which are actively used in the presentation of information:

the ability to store a large volume of various information on a single medium (up to 20 volumes of author's text, about 2000 or more high-quality images, 30-45 minutes of video recording, up to 7 hours of audio);

The ability to increase (detail) the image or its most interesting fragments on the screen, sometimes in twenty-fold magnification while maintaining the image quality. This is especially important for the presentation of works of art and unique historical documents;

The ability to compare images and process them with various software tools for research or educational purposes;

The ability to highlight "hot layers" in the accompanying image text or other visual material for which you can immediately get reference or any other explanatory (including visual) information (hypertext and hypermedia technologies);

The ability to perform continuous music or any other audio accompaniment corresponding to a static or dynamic visual series;

The ability to use video clips from movies, videos, etc., the "freeze frame" function, frame-by-frame" scrolling " of the video;

The ability to include databases, image processing techniques, animation (for example, accompanying a story about the composition of a picture with a graphic animation demonstration of the geometric structures of its composition), etc.;

Ability to connect to the global Internet network;

Ability to work with various applications (text, image and sound editors, map information);

Ability to create your own "galleries" (selections) from the information presented in the product ("pocket" or "my notes" mode");

The ability to "remember the way you have traveled" and create "bookmarks" on the screen page that interests you";

The ability to automatically view the entire content of the product ("slide show") or create an animated and voiced "guide-guide" for the product ("speaking and showing user instructions"); the inclusion of game components with information components in the product;

The ability to" freely " navigate through the information and exit to the main menu (enlarged content), to the full table of contents, or even from the program at any point in the product.

2) The major carriers

Multimedia products are used as media that can store a huge amount of various information. Typically, multimedia products are focused either on computer media and playback media (CD-ROM), or on special set-top boxes (CD-i), or on telecommunications networks and their systems.

CD-ROM ( CD-Read Only Memory) is an optical disk designed for computer systems. Among its advantages - the versatility inherent in the computer, among the disadvantages-the lack of the ability to replenish information - its "re-recording" to disk, not always satisfactory playback of video and audio information.

CD-i (CD - Interactive) is a special compact disc format developed by Philips for TV set - top boxes. Among its advantages - high quality playback of dynamic video information and sound. Among the disadvantages - the lack of multi-functionality, poor quality of static visual information playback, associated with the quality of TV monitors.

Video-CD (TV CD format)-replacement of video cassettes with much higher image quality. Among the disadvantages is the lack of multi-functionality and interactivity (which it was not designed for when it was created).

DVD-i (Digital Video Disk Interactive) is a format of the near future that represents "interactive TV" or cinema. In General, a DVD is nothing more than a compact disc (CD), only faster and much larger capacity. In addition, a new sector format, more reliable error correction code, and improved channel modulation have been applied. The video signal stored on a DVD-video disc is obtained by compressing the Studio video signal CCIR-601 according to the MPEG-2 algorithm (60 fields per second with a resolution of 720x480). If the image is complex or changes quickly, there may be noticeable compression defects such as splitting or blurring of the image. The visibility of defects depends on the correct compression and its value (data flow rate). At a speed of 3, 5 MB/s, compression defects are sometimes noticeable. At a speed of 6 MB / s, the compressed signal is almost identical to the original. The main drawback of DVD video as a format is the presence of a complex copy protection scheme and regional blocking (a disk purchased in one part of the world may not play on a DVD device purchased in another part of the world.

Another problem is that not all existing DVD-ROM drives on the market today read discs with movies recorded for household readers.

Goals of using products created in multimedia technologies

The main goals of using products created in multimedia technologies (CD-ROMs with information recorded on them) are:

Popularization and entertainment (CDS are used as home libraries for art or literature).

Scientific-educational or educational (used as teaching AIDS).

Research - in museums and archives, etc. (used as one of the most advanced media and "repositories" of information).

3) Promotional purpose

Perhaps the widest use of multimedia products for this purpose is not in doubt, especially since popularization has now become some equivalent of advertising. Unfortunately, many developers sometimes do not understand that the simple use of a well-known media (CD-ROMa) and software does not yet provide a truly multimedia character of the product. Nevertheless, we have to admit that the "multicolored" of the presented works is a reflection of the existing public consciousness in the Humanities.

4) Scientific and educational purpose

The use of multimedia products for this purpose goes in two directions:

The selection of those products that can be used in the relevant courses through extremely rigorous analysis from existing market products. As practice shows, the selection task is extremely difficult, since only a few finished products can meet the subject of the courses taught and the high requirements for reliability, representativeness and completeness of the material, which are usually imposed by teachers. This is due to the fact that "subject matter specialists" who have the necessary knowledge in the presented field do not participate in the creation of products. And those few authors who try to work together with technical staff to create such multimedia products do not know the specifics of this computer genre and the psychology of perception of information presented on the computer screen.

Development of a multimedia product by teachers in accordance with the goals and objectives of training courses and disciplines.

5) The research objectives

There is clearly a confusion of terminology. In "pure" scientific developments, software is really actively used, which is also used in products created on the basis of multimedia technology. However, this technology itself can hardly meet the conditions and process of scientific search, which implies the dynamic development of the process of knowledge, since it fixes a single-stage state or achieved result, without giving the opportunity to change anything in it. In this sense, these tools can only be used at the stage of publishing the results of the study, when we get a multimedia product instead of the usual "hard" printed publications. The most obvious and almost automatically recalled area of application of multimedia products in the research field is electronic archives and libraries - for documenting collections of sources and exhibits, cataloging and scientific description, creating "insurance copies", automating search and storage, storing data on the location of sources, storing reference information, providing access to non-Museum databases, organizing the work of scientists not with the documents themselves, but with their electronic copies, etc.). the development and implementation of these areas of archival and Museum scientific work is coordinated by the International Committee on documentation (CIDOC) under the International Council of museums, The Museum's computer network under the Committee for the computer exchange of Museum information (CIMI), as well as the Getty International program in art history (AHIP). In addition, these organizations are engaged in the development of common international standards for documenting and cataloging Museum and archival values, the implementation of opportunities for the exchange of information components of research systems.

MULTIMEDIA is a buzzword in the computer world. The term MULTIMEDIA defines the cherished dream of most computer users. This concept defines information technology based on a software and hardware complex that has a core in the form of a computer with means of connecting audio and video equipment to it. Multimedia technology allows us to combine computer capabilities with traditional means of presenting audio and video information for the synthesis of the three elements when solving problems of intellectual activity automation

The tasks to be solved cover all areas of intellectual activity: science and technology, education, culture, business, and are also used in the service environment when creating electronic guides with immersion in a real environment, multitecs. Until the end of the 80s, multimedia technology was not widely used in our country due to the lack of hardware and software support. In the early 90's, relatively inexpensive multimedia systems based on IBM PC appeared in our country, and the myth of multimedia technologies became a reality. One of the main areas of application of multimedia systems is education in the broad sense of the word, including such areas as video encyclopedias, interactive guides, simulators, situational role-playing games, etc. A computer equipped with a multimedia Board immediately becomes a universal training or information tool for almost any branch of knowledge and human activity - just install a CD-ROM with the appropriate course in it (or put the required files on a hard drive).

There are great prospects for multimedia in medicine: knowledge bases, methods of operations, catalogues of medicines, etc. In the business sector, real estate firms are already using multimedia technology to create catalogs of homes for sale - the buyer can see the house on the screen in different angles, make an interactive video tour of all the premises, get acquainted with the plans and drawings. Technology sultimedia enjoys great attention of the military: for example, the Pentagon is implementing a program for transferring all technical, operational and training documentation on all weapons systems to interactive video disks, creating and mass using simulators based on such disks.

Companies that specialize in the production of hypermedia publications-books, encyclopedias, and guidebooks-are quickly emerging.

Among the well-known products of the "encyclopedic" plan-published in France by the society Act Informatic "Electronic dictionary"," Electronic encyclopedia " Grolier, Information Finder company World Book. All the properties of multimedia has a complete encyclopedia "Birds of America". All color images and accompanying text were taken from the original first edition. The user hears the voices of birds recorded on a disk with the help of the Cornell University library of natural sounds.

The relatively large volume of the CD makes it an ideal medium for encyclopedic publications. The user "travels" through the encyclopedia using the keyboard or using graphic images, which include photos, maps, hint screens, electronic bookmarks, and a dictionary consisting of 150,000 articles.

An example of the use of multimedia in art can be "music CD-ROMs, which allow you not only to listen (with the highest quality) to the works of a particular composer, but also to view the scores on the screen, select and listen to individual themes or instruments, get acquainted with reviews. View text photos and videos related to the life and work of the composer, the composition and location of the orchestra and chorus, the history of the device of each instrument of the orchestra, etc. In particular, CD-ROMs dedicated to Beethoven's 9th Symphony, Mozart's "Magic flute", and Stravinsky's "sacred Spring" were released. Another example is the recording of art Museum collections on interactive video discs; this work is already underway in Russia.

In addition to " informational "applications," creative " ones should also appear, allowing you to create new works of art. Even now, the multimedia station is becoming an indispensable author's tool in film and video art. The author of the film behind the screen of such a desktop system collects, "oranges", creates works from pre-prepared - drawn, filmed, recorded, etc. - fragments. It has almost instant access to every frame of footage, the ability to dialog "electronic" editing with accuracy to the frame. It is subject to all sorts of video effects, image overlays and transformations, manipulations with sound, "assembling" sound from sounds from various external audio sources, from the sound Bank, from sound effects programs. Further, the use of computer-generated or processed images can lead to the emergence of new visual techniques in painting or cinema.

The implementation of artificial intelligence elements in the multimedia system looks very promising. They have the ability to "feel" the communication environment, adapt to it and optimize the process of communication with the user; they adapt to the readers, analyze their range of interests, remember issues that cause difficulties, and can themselves offer additional or clarifying information. Systems that understand natural language and speech recognizers further expand the range of interaction with the computer.

Another fast-growing field of computer applications that is already quite fantastic for us, in which multimedia technology plays an important role, is virtual or alternative reality systems, as well as "telepresence" systems close to them. With the help of special equipment-a system with two miniature stereo displays, headphones, special touch gloves, and even a suit, you can "enter" a computer-generated or simulated world (rather than look into it through a flat window of the display), turning your head, look to the left or right, go further, extending your hand forward - and see it in this virtual world; you can even take a virtual object (feeling its weight) and move it to another place; you can thus build, create this world from within.

TYPES OF MULTIMEDIA INFORMATION DATA AND THEIR PROCESSING TOOLS:

MPS standard (more precisely, the tools of the Multimedia Windows software package - an operating environment for creating and playing multimedia information) provide work with various types of multimedia data.

Multimedia information contains not only traditional statistical elements such as text and graphics, but also dynamic elements such as video, audio, and animation sequences.

STILL PICTURE. This includes vector graphics and bitmap images; the latter include images obtained by digitizing using various capture boards, grabbers, scanners, as well as computer-generated or purchased as ready-made image banks. The maximum resolution is 640 * 480 with 256 colors (8 bits / pixel); this image takes about 300 KB of memory; compression is not provided as standard; loading one image on a CD-ROM takes " seconds. Tools for working with 24-bit color are usually included in the accompanying software for certain 24-bit video boards; such tools are not yet available in Windows. A person perceives 95% of the information coming to him from the outside visually in the form of an image, that is, "graphically". This representation of information is by its nature more visual and easier to perceive than a purely textual one, although the text is also a graphic. However, due to the relatively low bandwidth of existing communication channels, the passage of image files through them requires considerable time. This forces us to focus on data compression technologies, which are methods for storing the same amount of information by using fewer bits. Optimization (compression) - presenting graphical information in a more efficient way, in other words, "squeezing the water out" of their data. You need to take advantage of three generalized properties of graphical data: redundancy, predictability, and optional. A scheme similar to group encoding (RLE) that uses redundancy says: "here are three identical yellow pixels", instead of "here's a yellow pixel, here's another yellow pixel, here's the next yellow pixel". Huffman algorithm encoding and arithmetic encoding based on a statistical model uses predictability, assuming shorter codes for more frequently occurring pixel values. The presence of optional data implies the use of a lossy encoding scheme ("JPEG lossy compression"). For example, random viewing by the human eye does not require the same resolution for color information in the image that is required for intensity information. Therefore, data that represents a high color resolution may be excluded. But this is not an interesting theory, and as for practice, the graphics intended for publication on the Internet must be pre-optimized to reduce its volume and as a result, traffic. Unfortunately, there are nodes in the network with completely "unsightly" graphics. When I get to such a place, I personally try to get away from it as quickly as possible or turn off the graphics display in the browser. In this way, the node owner obviously puts himself at a disadvantage. All his efforts to" decorate " the page remain unclaimed, moreover, he loses potential customers. Network graphics are mainly represented by two file formats - GIF (Graphics Interchange Format) and JPG (Joint photography Experts Group). Both of these formats are compression formats, meaning the data in them is already compressed. Compression, however, is a matter of choosing the optimal solution. Each of these formats has a number of configurable parameters that allow you to control the quality-size ratio of the file, so by deliberately reducing the quality of the image, often with little effect on perception, to achieve a reduction in the size of the image file, sometimes to a significant extent.GIF supports 24-bit color, implemented as a palette containing up to 256 colors. Features of this format include the sequence or overlap of multiple images (animation) and display with alternating rows (Interlaced). Several customizable GIF format parameters allow you to control the size of the resulting file. The greatest influence is the depth of the color palette. A GIF file can contain from 2 to 256 colors. Accordingly, a smaller content of colors in the image (the depth of the palette), all other things being equal, gives a smaller file size. Another parameter that affects the size of the GIF file is diffusion. This allows you to create a smooth transition between different colors or display a color that is not in the palette by mixing pixels of different colors. The use of diffusion increases the file size, but this is often the only way to more or less adequately transmit the original drawing palette after reduction. In other words, the use of diffusion allows you to reduce the depth of the GIF file palette to a greater extent and thus contribute to its "simplification". When creating an image that will later be converted to GIF format, you should consider the following feature of the LZW compression algorithm. The degree of compression of graphic information in GIF depends not only on the level of its repeatability and predictability (a single-color image has a smaller size than a randomly "noisy" one), but also on the direction, since the image is scanned line by line. This is clearly seen in the example of creating a GIF file with a gradient fill. For example, there are two drawings. All other things being equal, a file with a vertical gradient is compressed by 15% more than a file with a horizontal gradient (2.6 KB vs. 3.0 KB). In fact, there is no JPG format per se. In most cases, these are JFIF and JPEG-TIFF files compressed using JPEG compression technologies. However, this does not matter much in practice, so we will stick to the generally accepted terminology. The lossy JPEG compression algorithm does not handle images with a small number of colors and sharp transition borders very well. For example, an image or text drawn in an ordinary image editor. For such images, it may be more effective to present them in GIF format. At the same time, it is indispensable when preparing for web publishing of photos. This method can restore a full-color image that is almost indistinguishable from the original, while using about one bit per pixel to store it.The JPEG compression algorithm is quite complex, so it works slower than most others. In addition, this type of compression includes several technologies that are similar in their properties to JPEG. The main parameter present in all of them is the image quality (Q-parameter) measured as a percentage. The size of the output JPG file is directly dependent on this parameter, i.e. when the "Q" is reduced, the file size decreases.