Lecture 1 Overview And DIP

Question 1

What is the most commonly used numeral system?

Answer 1

Decimal numeral system

Question 2

How many possible values of a digit do decimal numeral system have?

Answer 2

10
0,1,2,3,4,5,6,7,8,9

Question 3

What numeral system do computers write and read numbers?

Answer 3

Binary numeral system

Question 4

How many possible values of a digit do binary numeral system have ?

Answer 4

2
0,1

Question 5

What do 1k means in binary numeral system?

Answer 5

1024

Question 6

What is the basic unit of digital data?

Answer 6

Byte (B)

Question 7

1 byte = ? Bit

Answer 7

8 bits (b)

Question 8

What is the range and number of bytes of an unsigned 8 bot integer (uint8)?

Answer 8

Range = 0 to 255
Byte = 1

Question 9

What is the range and number of bytes of an unsigned 16-bit integer (uint16)?

Answer 9

Range = 0 to 65535
Bytes = 2

Question 10

What is the range and number of bytes of a signed 8-bit integer (int8) ?

Answer 10

Range = -128 to 127
Byte = 1

Question 11

What is the range and number of bytes of a signed 16-bit integer (int16) ?

Answer 11

Range = -32768 to 32767
Bytes = 2

Question 12

What do the class [double] means in classes of digital data?

Answer 12

The class double means floating point number with double precision. The number of byte is 8 bytes = 64 bits.

Question 13

What is the importance of the most significant bit of signed-bit integer?

Answer 13

In signed integer, the most significant bit carries the negative sign

Question 14

What is the definition of discretisation?

Answer 14

The projection of real world object in continuous-space continuous-value onto an image in discrete-space discrete-value.
Discretisation is a process changing analog data into digital data.

Question 15

By what method can analog data changes to digital data (I.e. discretisation) ?

Answer 15

1. Spatial sampling
2. Amplitude quantisation

Question 16

What is the problem of discretisation of data?

Answer 16

It creates discrepancy from the original signal.

Question 17

What can be done to reduce discrepancy of the image from the original signal?

Answer 17

Increase bit depth
Improve density resolution
Increase bit per pixel

Question 18

What do number of bits per pixel determines in a digital image?

Answer 18

The number of bits per pixel determines the number of intensity levels.

Question 19

The origin of a grayscale image starts from which corner?

Answer 19

Left top corner

Question 20

What is the wavelength of visible light?

Answer 20

400-700 nm

Question 21

What is the responsibility of cones cells and rod cells respectively in visual perception?

Answer 21

Cone cells = sensitive to colour
Rod cells = sensitive to intensity

Question 22

What are the three primary colours?

Answer 22

Red green blue

Question 23

Name the two Color reproduction systems.

Answer 23

Additive and subtractive

Question 24

Mixing two primary colours gives a ________________.

Answer 24

Secondary colour

Question 25

Secondary colour is __________________ to a primary colour

Answer 25

Complementary

Question 26

What are the three secondary colours?

Answer 26

Magenta cyan and yellow

Question 27

When all primary adds together it shows ___________.

Answer 27

White

Question 28

When all primary colour light is absorbed it shows ___________.

Answer 28

Black

Question 29

What are the 4 colours in 4 colour printing?

Answer 29

CMYK Cyan magenta yellow and black

Question 30

What is HSV cone?

Answer 30

H = hue : ring S = saturation : radius V = Value of brightness : diagonal

Question 31

What is the central axis of the HSV cone represents?

Answer 31

Grayscale

Question 32

How many bit in a colour pixel?

Answer 32

24 bit (I.e. 8 x 3) (RGB)

Question 33

What are the descriptive parameters of image quality?

Answer 33

1. Density resolution (Bit depth) 2. Contrast 3. Spatial resolution 4. Signal-to-noise ratio (SNR) 5. Artefacts

Question 34

What is the difference between luminance and brightness?

Answer 34

Luminance is the measure of the actual density, independent to the surroundings. unit = cd/m2 Brightness is the perceived luminance by rod cells, it is affected by the surrounding and background

Question 35

What is the definition of contrast?

Answer 35

It is the measure of differences in brightness in adjacent regions of the image

Question 36

What is the definition of spatial resolution?

Answer 36

How fine the pixels in the image I.e pixel size (mm)

Question 37

2 Formula of signal-to-noise ratio

Answer 37

………..