Multimedia Systems

views updated

MULTIMEDIA SYSTEMS

Multimedia can be defined as any application that combines text with graphics, animation, audio, video, and/or virtual reality. A computer system is a combination of equipment (hardware), processes and programs (software), and people organized to perform a function. Combining these definitions, a business multimedia system includes equipment, programs, and people organized for the purposes of communication, data storage and retrieval systems (multimedia databases and electronic filing systems), information security, and Internet use (Web pages and electronic-business applications).

Within organizations, multimedia systems are used in all forms of information systems from transaction processing systems to executive decision support systems. These systems also can be found across industries such as accounting, banking, communications, education, entertainment, insurance, manufacturing, medical, retailing, and real estate. Anywhere there is a need for combining text, pictures, sounds, and animation, multimedia systems are found.

Multimedia systems are used for security to keep intruders out of a system and for the protection of stored documents. Scanning devices are available to scan potential user's eyes (retina imaging) or thumb prints to gain access to a computer or site. Other systems can scan a person's signature or capture voice pattern recognition for the same purposes. Stored text, pictures, original document images, sound files, and video files can be protected through encryption methods, read/write protection, password management, and copyright protection that keep intruders from copying or accessing sensitive files.

ANALOG SYSTEMS

Analog multimedia systems use books, documents, films, photographs, records, tapes, videotapes, and many other forms of media to store text, sounds, and pictures. As technology improves, converting from one medium to another and combining different media formats becomes difficult and cumbersome.

Analog systems are being replaced with systems that digitize the original documents and store them on digital media; nevertheless, analog systems still remain vital for legal, historical, and research purposes. Many new companies have come into existence for the sole purpose of converting analog media into digital formats.

COMPUTER-BASED MULTIMEDIA

Technological advances have changed the hardware and software used for developing multimedia from the traditional analog equipment to computer-based or digital multimedia systems. Computers use 0s and 1s to store and process sounds, still graphics (pictures), and motion video. Text scanning, digital imaging (using digital cameras and scanners), sound cards, and analog video-capturing devices sample, compress, and convert analog media into a series of 0s and 1s (digital) signals for processing by a computer. Once analog media are converted to a digital format, a computer can be used to manipulate the various media. With the development of digital-video cameras

and digital-still cameras, media are already in a form that the computer can process, making it easier to merge text, graphics, video, sounds, and animation into an application.

Multimedia hierarchy is a term that reflects how much computing power is needed to process information. Multimedia systems have different levels of components that handle tasks ranging in difficulty from simple text processing to complex digital-motion video. As more powerful computers are developed, more applications can be used by businesses.

TEXT PROCESSING

Text is the first and simplest level in the multimedia hierarchy. Traditionally, text has been keyed directly into the computer. Scanners equipped with optical character recognition software allow text to be scanned into a computer from printed documents or from Universal Product Codes on products, using wand or handheld scanners.

More complex text input involves voice pattern recognition systems that convert voice to text. These applications find their way into legal, health-care, and other industries and businesses that process vast amounts of text. Text-to-voice systems reverse this process and allow text to be read to the user.

SOUND PROCESSING

Sound in multimedia applications enables a user to describe products, give instructions, enhance a presentation, or provide cues for some action by the viewer. Hardware for capturing and processing sounds includes a card attached to the main motherboard of the computer system.

Sound cards capture analog audio signals from microphones, music compact disks, musical instrument digital interface (MIDI; such as electronic-piano keyboards) devices, and other sound sources through a line-in jack on the card. Computer users can plug in record turntables, cassette tape players, or any other analog device from an audio-out jack on those devices and record sounds. Sound cards also have output jacks for speakers, or the audio-out can be plugged into other sound recording devices. The card contains two computer chips called the AD (analog to digital) and DA (digital to analog) chips. These chips convert sound waves to digits and digits to sound waves.

Sound application software is used to select devices and to capture, edit, and save sounds in digital files. Users can add effects such as fade-in, fade-out, and the echo effect to the digital-sound clip. Several competing file storage standards or extensions exist for computer sound files. These standards depend on the manufacturer of the hardware or developers of the software. The more a given standard is used, the more portable the file is to other users and to Internet applications.

STILL-IMAGE PROCESSING

Various specialized forms of multimedia include imageprocessing systems designed specifically for handling business forms, images, graphics, or pictures. An example may be found in banking systems that use computer-output microform devices to store images of checks and place several check images on the customer's bank statement or display them on an Internet banking page, rather than returning the canceled checks. Insurance companies use imaging systems to scan insurance applications, claim forms, and pictures of damages to customers' property. The imaging systems provide immediate access to all information stored in a computer for processing of a claim. In transaction-processing systems, companies can digitize customer signatures on sales slips and store the original sales documents for proof of purchase using point-of-sale devices. Other "turnaround documents" may be generated by a computer and scanned into a computer to verify a purchase at a merchandise pickup point.

Scanners and digital cameras can also be used in image processing to capture pictures for printed publications, Internet Web sites, and electronic presentations. A scanner or digital camera can digitize a picture by converting dark and light areas of a graphic to dots or pixels using a charge-coupled device. File sizes can be reduced by saving graphics using compression/decompression (codec) systems such as JPEG (Joint Photographic Experts Group) compression methods. Single images can also be "captured" with a video-capture board from videotape, from a video camera, or directly from broadcast television. In both cases, a file is then saved in computer format for future use.

Photographic editing software lets users add special effects and edit photos or images. Draw and paint computer programs generate graphics and tables for multimedia applications. These programs allow users to draw objects, fill them with colors, and add text and special effects. The user-made images are saved in files and are then incorporated into a multimedia application.

FULL-MOTION VIDEO PROCESSING

In the early twenty-first century, broadcast television and videotapes record moving pictures by using 30 still pictures or frames for every second of motion. Broadcasts and videotapes use a standard developed in the 1950s in the United States, the National Television Standards Committee broadcast standard. Other countries use 25 frames per second and have different image-aspect ratios (ratio of height to width). At the start of the twenty-first century, the high-definition and digital television broadcasting being introduced will change the standards; pictures will have better quality because of an increase in the number of pixels and a change in the aspect ratio of the picture.

More expensive tuner and capture cards on computers allow for "full-motion" capture by saving all of the frames and sound. Because these files become very large (640 × 480 pixels per frame times 30 frames per second—over 9 million characters for 1 second), several methods have been developed for compressing motion video files. Video is compressed to save it as a smaller file and is decompressed during playback. Several codec systems use hardware including computer chips and software such as MPEG (Motion Picture Experts Group). Since video files are large, they are usually brief recordings or clips from video. The clips are used in business presentations, on Web pages, as product descriptions, or as other media bytes to emphasize an important point in a short time. Advances in storage capacity and speed of newer storage media will eventually allow for smoother and longer clips. Video streaming from Web sites stores large video clips on the host Web site and allows the video to "stream" in smaller segments to the Internet user.

ANIMATION AND VIRTUAL REALITY

The most sophisticated forms of multimedia are animation and virtual reality. These systems combine still graphics, video, sound, and animation to form virtual-reality outcomes. Industries using this technology include entertainment, education and training, legal, architecture and construction, government, and transportation. Animated (anime) movies and computer games have become popular and require all of the multimedia formats for development.

Working with virtual reality requires powerful computers and software to collect, edit, and produce the product or title or presentation. Some examples include computer games, computer-assisted design, homeimprovement software that allows users to design and display a proposed project in 3-D, flight simulators, and simulation of a crash for accident investigation.

SUMMARY

Figure 1 summarizes how elements of multimedia are linked to a computer system to develop multimedia applications. Once in a computer (digitized), each element can be used with software to manipulate media files into a multimedia system.

Multimedia systems can be applied to all organizational levels and functional areas of a company and across types of businesses and industries. As technology improves, so will the applications of multimedia.