Questions tagged [terminology]
For questions about words, phrases and definitions that are specific to signal processing.
3
votes
1answer
27 views
Limiter, compressor, AGC, dynamics processor?
What are the primary differences between the usage or definitions of the terms “AGC”, “compressor”, “limiter”, and dynamics processor? They all seem to be forms of playing with gain knobs.
1
vote
2answers
31 views
Confused in difference between sequence versus signal?
I am learning basics of signals and systems with MATLAB
If i create a vector in matlab such that
x=[ 2 5 10 20], will it be considered a sequence or a signal?
As ...
1
vote
2answers
29 views
What is the technical term for the product of “number of pixels” and “number of channel per pixel”?
Assume I have m x n pixels of an RGB image. If I calculate 3mn, what is the name of quantity for this value?
0
votes
2answers
25 views
System Response Terminology
If I have a system specified by
$$P(D)y(t)=Q(D)x(t)$$
and I specify initial conditions $y(0^-)=a, \ y'(0^-)=b,\ x(0^-)=c$ does the term $x(0^-)=c$ correspond to the zero state response or zero ...
2
votes
2answers
46 views
What is energy in image processing?
There are several web articles on the topic, but, after having read them, I still don't know what "energy" is, in the context of computer vision (CV) and image processing (IP). It is related to ...
0
votes
1answer
28 views
What is the difference between domain and range filtering?
In the context of image processing, I have heard the expressions "domain filtering" and "range filtering". What do these terms refer to? What is the difference between them?
1
vote
1answer
34 views
What is a periodic signal in image processing?
In the context of image processing (and computer vision), the concept of convolution comes up a lot. Convolution is quite related to the concept of Fourier transform and DFT. In the context of image ...
0
votes
0answers
19 views
What is the relation between smoothing and blurring?
Is there any difference between smoothing and blurring? Are these two operations the same or do these terms refer to different operations?
0
votes
0answers
9 views
What is intuitively a diffusion in the context of images?
I have heard the word "diffusion" in the context of image processing and computer vision. However, images are discrete and I associate the word "diffusion" with a continuous process. Intuitively, what ...
0
votes
1answer
42 views
What is the relation between time, frequency, spatial and spectral domains?
What is the relation between time, frequency, spatial and spectral domains?
I think that time and spatial domains are the "original" domains (e.g. if the signal is a greyscale image, then the domain ...
1
vote
1answer
76 views
What do we mean by spectrum?
Consider the context of image processing and computer vision, and, in particular, discrete Fourier transform.
For example, in the sentence
In the Discrete Time Fourier Transform the forward ...
2
votes
0answers
32 views
What is the difference between an impulse response and a kernel?
It seems to me they are two terms used to refer to the same concept, but, according to the Wikipedia page on Guassian filter
a Gaussian filter is a filter whose impulse response is a Gaussian ...
1
vote
2answers
69 views
Is there any opposite name for Decibel?
According to definition of decibel it’s “logarithmic unit of measurement used to express”
So in audio we often convert linear value from range 0 to 1 to logarithmic scale for example like that:
<...
-2
votes
2answers
42 views
difficulty in understanding amplitude, frequency and period
I have difficulty in understanding of some fundamental terms as amplitude. Can be there more than one amplitude for a signal? The following expression is combination of 3 sinusoidal signal, so are ...
2
votes
1answer
115 views
Quadrature demodulation, homodyne detection, lock-in detection - what's the difference?
Quadrature demodulation
Homodyne detection
Lock-in detection
What is the difference between these terms? Are they all synonomous? In my mind they kind of are, so I'm never sure which to use.
I ...
1
vote
0answers
20 views
Does Mutual information utilize spatial information to calculate image similarity?
To calculate images similarity based on Mutual Information (MI), histogram and join histogram is required. In the literature, there are 2 contradict opinions about MI operation. 1. MI does not utilize ...
0
votes
1answer
63 views
Is Oversampling a Signal Same as Discretizing the Signal?
I am confused about the new terminology 'oversampling' I have encountered very recently.
To explain it better, I am going to use numerical examples.
Now let's assume I am using a BPSK modulator and my ...
1
vote
1answer
111 views
Intuition behind cepstrum analysis terminology
In multiple books I found a parallel between spectrum-analysis terminology and cepstrum-analysis terminology that says
low pass filter $\rightarrow$ short pass lifter
I didn't read explicitly what ...
2
votes
4answers
85 views
What is the moment when all oscillators aligned to make a jump called?
Say we have a square wave and its Fourier series. When the wave doesn't jump, its oscillators aren't aligned:
But if they are aligned, the wave will jump:
What is this moment called? They might not ...
0
votes
2answers
85 views
The precise meaning of 'coefficient' in signal processing
when I read papers on signal processing, I often see the term 'coefficient' being used to refer directly to 'samples', i.e. "We can reduce the number of coefficients, by simply subsampling the even ...
3
votes
1answer
56 views
Is there a name for the procedure of taking the FT over separate consecutive small time-blocks?
Suppose we have a continuous time-interval $I=[a,b]$, and a signal $x \colon I \to \mathbb{R}$.
A procedure that is sometimes carried out (e.g. when doing bispectral analysis) is to partition $I$ ...
4
votes
1answer
153 views
Is there a name for $f(x) = |x|^n \cdot \operatorname{sgn}(x)$?
I'm looking for a name for the following function
$$f(x) = |x|^n \cdot \operatorname{sgn}(x)$$
which is the exponent function, but with the sign stripped from the input and reattached to the output....
1
vote
2answers
364 views
When can the impulse response become zero?
The article Efficient Use Of Sparse Adaptive Filters (Proc. Asilomar Conference, Khong et al., 2006) introduces adaptive filters for the estimation of channels or systems having a sparse impulse ...
4
votes
2answers
460 views
What is the meaning of channel capacity?
If the transmitted information signal takes values from a modulation constellation, then is there a way to know what the channel capacity is?
Is there a connection between the modulation kind and ...
0
votes
1answer
71 views
What is perfect and imperfect channel?
Often in estimation of the input signal to an unknown channel, the bit error rate is plotted as the performance measure. The curve is compared with an ideal curve labelled as 'Perfect channel'. For ...
0
votes
2answers
41 views
Confusion regarding model order and lags
I have similar questions as the one asked in these posts: https://stackoverflow.com/questions/47083890/fir-filter-length-is-the-intercept-included-as-a-coefficient-matlab/47085339?noredirect=1#...
1
vote
2answers
75 views
Why use parametric based estimation methods - confusion regarding terms
Using the probability density function (pdf) we can estimate an unknown parameter using methods such as Maximum Likelihood estimation. If the pdf is not available, then Least Squares can be used. ...
1
vote
2answers
63 views
Why maximum likelihood estimation method is taken as the benchmark for comparing with other methods?
In many research articles the performance of an estimation method is compared to that of the ML estimation performance. If the performance of the method does not achieve the ML estimation performance, ...
3
votes
1answer
2k views
Difference between order and length of a filter
Let, the channel be modeled as a FIR model with order L. Mathematically, $y_n = \sum_{k=1}^L h_k u_{n-k} \tag{1}$ where $u$ is the data input to the channel and <...
1
vote
1answer
601 views
SNR for complex valued signal and when to use SNR and when to use Eb/N0?
This question is in continuation to the one asked earlier Help in understanding the formula of Signal-to-Noise-Ratio (SNR) - Part 1
Consider a model
$$y[n] = x[n] + w[n]$$
Signal means the desired ...
0
votes
1answer
127 views
What is Audio codec in simplified term?
I am trying to understand what a codec actually is
Wikipedia says
In hardware, audio codec refers to a single device that encodes analog
audio as digital signals and decodes digital back ...
0
votes
1answer
95 views
Brief introduction to wireless communication and communication terminologies [closed]
In the Question Design of equalizer for wireless communication the diagram of a basic communication system is presented with informative points and discussions. My Questions are:
Considering the ...
2
votes
1answer
126 views
Terminologies - lags, order in time series model
I am facing some difficulties with the terminologies - lag ($p$) and sequence length (number of data points) (N) used in time series model such as Moving average and Autoregressive model. Considering ...
2
votes
1answer
107 views
Is there a scientific name for this technique?
The following algorithm takes a set of signals, and return a complex number:
For a given set of signals - $\{s_1(n),s_2(n),...,s_M(n)\}$, compute the DFT of each of them - $\{S_1(k),S_2(k),...,S_M(k)\...
2
votes
1answer
899 views
Lloyd Max quantization and clustering : Part 1
The Lloyd-Max quantizer is a scalar quantizer which can be seen as a special case
of a vector quantizer (VQ) designed with the Linde Buzo
Gray (LBG) algorithm.
In k-means clustering, we are given a ...
3
votes
2answers
1k views
Radar terminology - Specific meaning of “video signal”
In the radar literature, particularly in older references, the term "video signal", "downrange video", or just "video" is used to describe the radar signal at a certain point in the processing chain. ...
1
vote
1answer
2k views
Radar signal processing - Difference between range gate/range bin
In learning about radar signal processing, I see two different terms that sometimes seem to refer to the same thing, but sometimes different things:
Range gate
Range bin
Usually, I interpret both to ...
3
votes
1answer
198 views
Help in understanding from book expression of variance of an estimator : PRBS vs real valued input
The question is based on Book : Fundamentals of Statistical Signal Processing by Steven Kay, Chapter 4 : Eq(4.21). The expression for the variance of the estimated coefficients when the input is PRN ...
2
votes
1answer
127 views
What do certain terms mean in EEG processing describing frequency bands?
I've recently started a project about detecting driver drowsiness with an EEG and came across some terms I didn't quite understood:
...increase in theta activity occur... - ...low voltage theta ...
3
votes
1answer
128 views
White noise gain of uniform spline interpolation
Uniform spline interpolation is fully defined by its continuous-domain impulse response. I noticed that the integral of the square of the impulse response over its support gives the average ...
25
votes
5answers
7k views
Is there a technical term for this simple method of smoothing out a signal?
Firstly, I am new to DSP and have no real education in it, but I am developing an audio visualization program and I am representing an FFT array as vertical bars as in a typical frequency spectrum ...
1
vote
0answers
69 views
Why is the term deconvolution used more for signals and not so much (or at all) for systems?
Wikipedia defines mathematical deconvolution here, and with the examples given and my experience, what I've read over the years is that deconvolution is used to determine an input signal provided a ...
3
votes
1answer
234 views
What do you call it when you add zeros between the elements of a vector?
What do you call it when you add zeros between the elements of a vector?
let's say you have x =[1 2 3 4]
and ...
1
vote
0answers
17 views
How is per-class rate defined?
I've recently read the following
For our pixel labeling, consistent with [20], we report the
number of pixels correctly classified (per-pixel rate) and the
average of per-class rates. The per-...
0
votes
1answer
110 views
Terminologies: Adaptive, recursive and iterative
Considering non-linear filtering technique like Extended Kalman filtering with Expectation Maximization (EM). EM is an iterative technique but what is Kalman filtering? Is Kalman Filtering called ...
4
votes
3answers
3k views
What does 'canonical' mean?
What does 'canonical' mean?
e.g. 'write IIR or FIR in canonical form'
I get the gist of it but maybe someone here has a precise definition. In a non-DSP context it would mean something like '...
-1
votes
1answer
65 views
Terminology: source and target
How should one choose between the words "source" and "target"?
This video processing plugin from Sony Vegas tries to match the color of one video to the color of another. It got me confused because I ...
2
votes
2answers
518 views
Is there a difference between Image Alignment and Stereo Rectification for stereo correspondence or matching?
As far as I know,
Image alignment just finds the best fit given two images of the same scene.
Whereas Image rectification, with regards to stereo vision, warps the images so that the epipolar lines ...
1
vote
1answer
136 views
Beginner level : Help with terminologies : smooting length, length of channel, channel equalization delay, blind system identification, equalization
Say the channel model is an univariate FIR filter with true coefficients $h=[1,a_1, a_2 ]$. I am learning algorithms for system identification and channel equalization. For this, I am implementing ...
3
votes
1answer
67 views
Sinusoidal Wave Terminology
Suppose I have a sinusoidal signal of the form $x(t) = a\sin\left(2\pi b(t-c)\right) + d$. I understand $a$ is the amplitude, $b$ is the wave number, and $c$ is the phase shift. I know that the term ...
