Signals Flashcards
continous signal
its level is known everywhere and at all times
analog signal
its level is infinite precision real number
digitization
process of transforming an analog signal into a digital
sampling
periodically measuring the signal’s level and producing a sequnce of finite-length with infinte-precision samples
quantization
converting samples to finite-precision numbers
reconstruction
process of transforming a digital signal into an analog
signals
variations of a physical quantity that encode information
one-dimensional signal
it can be mathematically presented as a function of a single independent variable
attenuation
reduction in a signal’s strenght
frequency
number of identical patterns(cycles) contained in a second
aliasing
result of undersampling
the Nyquist criterion or Shannon sampling theorem
The sampling frequency should be at least 2fmax
Nyquist rate
minimal sampling frequency, 2fmax
pixel
discrete points in 2D space
color resolution
the number of bits needed to represent the color of a pixel
discrete-space and discrete-color information
digital image
color resolutions:
binary or black and white
grayscale
true color or RGB
actuators
devices that expect an analog electrical input signal
device for digitization
ADC
device for reconstruction
DAC
