Multimedia Systems

Question 1

Online form - typical fields

Answer 1

1. Input fields:
   - text fields
   - password fields
   - checkboxes
   - radio buttons
   - sliders
2. Action buttons:
   - radio button

Question 2

Colour depth

Answer 2

Number of bits per pixel:

The more the colour depth, the more bits required to produce the image and thus more image file size. The more the colour depth, the more colours the image includes.

Question 3

Cell based vs. path based animation

Answer 3

Cell based:
- the whole clip is fully animated
- images are each produced in a separate “cell”
- each frame is individually animated
- have higher frame rates (30 fps)
- requires more processing power to work
- display of the clip will be smoother and fluid

Path based:
- usually only the foreground is animated with a still background
- lower frame rate (24 fps)
- do not require that much processing power

Question 4

Compression processes - images

Answer 4

1. lossy - alters the image (image quality loss)
2. lossless - does not alter the image (no image quality loss)
3. JPEG compression technique - blur hard edges of an image - lossy compression but tries to minimise the loss of quality ( :) )

Question 5

Compression/Decompression processes video

Answer 5

1. CODEC –> coder decoder
   software that compresses and decompresses digital video to make the file size smaller using appropriate CODEC to compress or decompress videos
2. Block based coding –> frames are split up into a series of forms

Question 6

VR applications (list and explain : ) )

Answer 6

1. head-sets/heads-up display
2. virtual worlds - education and training

Question 7

AI and ethics in multimedia

Answer 7

1. artists on the internet → issue of copyright, artists work can be placed into AI and manipulated
2. deliver biassed results
3. privacy of the data collected on individuals
4. AI taking over our jobs
5. changing our interactions and behaviour at work

Question 8

Morphing

Answer 8

One image is slowly faded/changed, pixel by pixel, until the second image emerges

Question 9

Distorting

Answer 9

Pixels of an image are changed by stretching or resizing so the image results in a different form

Question 10

Expertise in Multimedia systems (list)

Answer 10

• project managers
• system developers
• system designers
• content providers
• writers
• graphic designers
• illustrators and animators
• technical personnel

Question 11

Print vs Multimedia

Answer 11

• different modes of display
• interactivity provides user with a better experience
• involvement of participants
• ease of distribution
• authority of document

Question 12

Roles and skills required by a system designer

Answer 12

• oversee development in terms of the stages of system development
• plan and organise hardware and software
• preparing specifications
• require communication skills, management skills, skills in producing the system

Question 13

Roles and skills required by content providers

Answer 13

• provide the content for the multimedia (content = media in the display)
• experts in the subject matter of the project
• require skills in software to produce content

Question 14

How does a CRT screen work to display multimedia

Answer 14

• electron beams are ejected to produce the colour on the display by making the phosphor glow
• inner screen of the monitor is coated with phosphor that emits the light in the three primary colours

Question 15

How does a LCD screen work to display multimedia

Answer 15

• LCD’s are lit by a backlight
• pixels are switched on and off electronically while using liquid crystals to rotate polarised light

Question 16

Why are multimedia systems used?

Answer 16

to provide a more realistic and immersive environment for individuals (typically multimedia systems that use VR)

Question 17

How have advances in processing power influenced the development of multimedia systems?

Answer 17

–> faster CPU –> more interactive media and higher resolution displays

–>improved bandwidth –> allows streaming to multiple devices

–> powerful CPU–> faster compression and decompression–> developers can use more elements in the display

–> need for larger storage devices with faster access to store and retrieve data

Question 18

What is a pixel?

Answer 18

The smallest unit of an image that can be displayed and represented on a digital display device

Question 19

Describe animation

Answer 19

a rapid display of a sequence of images to create an illusion of movement. frame rates of about 24fps are needed to create this illusion

Question 20

ROM and RAM

Answer 20

ROM - read only memory –> holds data that are fixed at the time of construction, is non-volatile

RAM - random access memory –> data and instructions are held temporarily, is volatile and relies on power to maintain its contents

Question 21

Bit mapping

Answer 21

relationship between the image on screen and the bits stored in primary and secondary memory
- each pixel is described by one or more bits in memory

Question 22

Sampling Size

Answer 22

number of bits used to stored each sample from the analog sound wave

Question 23

Sampling rate

Answer 23

number of samples taken of the analog wave in 1 second

Question 24

Multimedia used in leisure and entertainment

Answer 24

allows for ingenious levels of interactivity and realism to captivate users of the product. here, the multimedia has realism, fast action and user input
- requires high level of graphics computing power

Question 25

Raster Scan in a CRT display

Answer 25

• phosphorus must be re-excited to maintain images in CRT display
• electron beams start from the top left-hand corner and move left to right and top to bottom in a zigzag pattern which is called a raster scan