Signals

Question 1

continous signal

Answer 1

its level is known everywhere and at all times

Question 2

analog signal

Answer 2

its level is infinite precision real number

Question 3

digitization

Answer 3

process of transforming an analog signal into a digital

Question 4

sampling

Answer 4

periodically measuring the signal’s level and producing a sequnce of finite-length with infinte-precision samples

Question 5

quantization

Answer 5

converting samples to finite-precision numbers

Question 6

reconstruction

Answer 6

process of transforming a digital signal into an analog

Question 7

signals

Answer 7

variations of a physical quantity that encode information

Question 8

one-dimensional signal

Answer 8

it can be mathematically presented as a function of a single independent variable

Question 9

attenuation

Answer 9

reduction in a signal’s strenght

Question 10

frequency

Answer 10

number of identical patterns(cycles) contained in a second

Question 11

aliasing

Answer 11

result of undersampling

Question 12

the Nyquist criterion or Shannon sampling theorem

Answer 12

The sampling frequency should be at least 2fmax

Question 13

Nyquist rate

Answer 13

minimal sampling frequency, 2fmax

Question 14

pixel

Answer 14

discrete points in 2D space

Question 15

color resolution

Answer 15

the number of bits needed to represent the color of a pixel

Question 16

discrete-space and discrete-color information

Answer 16

digital image

Question 17

color resolutions:

Answer 17

binary or black and white
grayscale
true color or RGB

Question 18

actuators

Answer 18

devices that expect an analog electrical input signal

Question 19

device for digitization

Answer 19

ADC

Question 20

device for reconstruction

Answer 20

DAC