Characteristics of Multimedia Systems

Exercise 7.1

1. A multimedia system is an information system that combines different types of media. It uses at least 3 media types, such as text, images, animation, audio and video. Multimedia systems have the potential to provide a better experience than any other information medium.

2. The types of media used in a multimedia product include text, numbers, hypertext, audio, images, animations and video.

3. The text media type refers to letters, numbers and other characters whose meaning is not specified. The number media type, on the other hand, refers to predefined characters, usually numerals, whose meaning and format are specified.

4. A hyperlink (or hotword) is a highlighted item that allows an electronic connection. The author of the hypertext must specify the location of the information accessed by each link. In a multimedia product, the link may be to text, an image, audio, animation or video. When you click on a link, you move from one document to another even if they are different media types.

5. Audio is an essential part of most multimedia products because it is used to explain concepts, reinforce selections and provide special effects.

6. Bit-mapped graphics produce good-quality images where shading and detail are needed. However, when transformed (resized or restretched), bitmapped graphics become ragged and suffer loss of resolution. Also, bit-mapped images require large amounts of storage.

7. Video starts with a continuous event and breaks it up into discreet frames, whereas animation starts with independent pictures and puts them together to form the illusion of movement.

8. Interactivity is the property of an information system that allows the user to choose the sequence and content of the information to be displayed.

9. Current images are stored in a section of memory called the frame buffer.

10. The sampling rate is the number of times a sample (slice) is taken from the sound wave, whereas the sampling size is the number of bits per sample.

11. The frame rate is the speed of an audio or animation. It is measured by the number of frames per second (fps).

12. Cell-based animation involves drawing and displaying individual frames or cells, which themselves are stored separately. Path-based animation, on the other hand, involves displaying the movement of objects onto a fixed background in a particular sequence or path.

13. Tweening is a key process is computer animation as it can generate the intermediate frames between two objects, greatly reducing the work required on the user’s part.

14. Morphing is an animation technique that involves the smooth change between two different images. It transforms the shape, size, dimension and colour of one image into those of another.

15. People involved in multimedia systems include:

  • Content providers are people who provide the material for the multimedia product. This may include text, graphics sketches or final drawings, video footage and audio tracks. Generally these people are skilled in their field without necessarily having any technical skills in the software or hardware areas.
  • System designers plan and organize the hardware and software required for the presentation. He or she may also act as the project manager or provide technical support.
  • Project managers organize the scheduling of various components of the product, provide overall supervision for the components and ensure that all components are delivered on time.
  • The technical staff includes a variety of artists and technicians who edit the graphic and video material, text and all other material into appropriate formats for the final document. It also includes layout and design personnel who work to develop an overall theme and look of the product. These people may also include the content providers, or they may be a totally separate group.

Learning Activities

1a. (640*480)/ (1024*8) = 37.5 Kb

b. (1024*768*6)/(1024*8) = 576 Kb

c. (1600*1200*16)/(1024*8) = 3750 Kb

d. (1280*1024*8)/(1024*8) = 1280 Kb

e. (1152*864*32)/(1024*8) = 3888 Kb

2a. (22050*8*120*2)/(8*1024*1024) = 5.05 Mb

b. (44100*16*180*2)/(8*1024*1024) = 30.28 Mb

c. (22050*16*60)/(8*1024*1024) = 2.52 Mb

d. (11000*8*240)/(8*1024*1024) = 2.52Mb

e. (44100*16*600*2)/(8*1024*1024) = 100.94 Mb

3a. (1024*768*16*25*7200)/(8*1024*1024*1024) = 263.67 Gb

b. (1600*1200*30*4500*32)/(8*1024*1024*1024) = 965.60 Gb

4a. (640*480*8)/(8*1024*1024) = 0.29 Mb

b. (640*480*16)/(8*1024*1024) = 0.59 Mb