Week 1 - Introduction, Perception, Images and Lab fundamentals

Question 1

What is multimedia?

Answer 1

Interactive, computer meditated presentation that includes at least 2 of the following:
Text, sound, still graphic images, motion graphics, animation.

Question 2

What are the primary functions of multimedia computers?

Answer 2

Development tools for multimedia creation - e.g. Adobe, Apple
Delivery devices for multimedia applications - Browsers or player applications

Question 3

What are the past uses of multimedia?

Answer 3

Multimedia was mainly limited to instructional material - Computer assisted instruction (CAI), Computer assisted learning (CAL)

Question 4

What are the uses of multimedia now?

Answer 4

Instruction
Entertainment
Scientific analysis, research and presentations
Business applications, advertising and sales
Art and other humanities purposes
Adaptive technologies for the disabled
Virtual reality

Question 5

What is perception?

Answer 5

“The consciousness or awareness of objects or other data through the medium of the senses.”

Question 6

List the electromagnetic spectrum from shortest to longest wavelength.

Answer 6

High energy -> Gamma rays, X-rays, Ultra-violet, Visible, Infra-red, Microwaves, TV, Radio Waves

Question 7

What is the equation for wavelength?

Answer 7

c = f(lamda)

Question 8

What is light usually measured in?

Answer 8

Radiance (watts) - Total amount of light emitted
Luminance (lumens) - Light strength that is perceived by the human eye
Brightness - Subjective measure of how bright an object appears to be

Question 9

What is the wavelength of visible light?

Answer 9

400-700 nm

Purple - blue - green - yellow - orange - red

Question 10

What are rods and how many do we have?

Answer 10

Light receptor cells that detect shades of black and white in the peripheral vision. Works well in the dark. We have roughly 120 million rods.

Question 11

What are cones and how many do we have?

Answer 11

Light-receptor cells that are sensitive to colour located mainly in the centre and only work in bright light. Sensitive to 3 bands of electromagnetic radiation. We roughly have 6 -7 million rods.

Question 12

What colours does the human eye respond to?

Answer 12

Humans are tri-chromatic and respond red, green and blue.

Question 13

What is an active display?

Answer 13

A display that emits a combination of Red, Blue and green light. Emits different wavelengths of light.

Question 14

What is a passive display?

Answer 14

Passive displays show colour by absorbing some wavelengths and reflecting others. Passive displays have Cyan, Magenta and Yellow (CMY) as the primary colours. Known as the subtractive colour system which absorbs RGB respectively.

Question 15

How sensitive is the eye to different colours?

Answer 15

0. 299 x Red
1. 587 x Green
2. 114 x Blue

Question 16

What is a colour gamut?

Answer 16

A graph specifying the ranges of colour a particular display can produce

Question 17

What are the models of colour the eye can respond to other than wavelengths?

Answer 17

Luminance or brightness - intensity (energy) of light
Excitation purity or saturation - how washed out or pure the colour is
Chromaticity or hue of light - purity and dominant frequency

Question 18

What are the psychophysical models?

Answer 18

Based on human perception

HLS - Hue, Lightness, Saturation

Question 19

What is saturation?

Answer 19

How much white light has been added to the colour, dominance of the hue - Excitation purity

Question 20

What is hue?

Answer 20

Perceived dominant wavelength - What colour it is

Question 21

What is the HSV colour colour model?

Answer 21

Saturation, hue, value

Question 22

What is value of light?

Answer 22

Brightness - perceived intensity of light - how light/dark it is (Energy)

Question 23

What is picture resolution?

Answer 23

Number of pixels or samples used to represent an image

Question 24

What does a higher resolution mean?

Answer 24

Higher resolution the better quality the image/bitmap is

Question 25

What does image resolution determine?

Answer 25

The quality and the storage requirements

Question 26

What does aspect ratio represent?

Answer 26

Number of horizontal pixels x vertical pixels

Question 27

How is data stored?

Answer 27

Data is stored using binary number which are either 1 or 0 an individual binary digit is referred to as a bit.

Question 28

Advantages and disadvantages of true colour

Answer 28

High quality but requires more memory

Question 29

Advantages and disadvantages of palette colour

Answer 29

Enables easier implementation of certain techniques but limited number of colours leading to lower quality