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1500 questions
7
votes
1 answer
How to choose FFT depth for ADC performance analysis (SINAD, ENOB)
I am trying to simulate a model of an ADC and determine its performance.
One of the interesting properties is the ENOB (Effective Number Of Bits), which can be calculated from SINAD (SIgnal-to-Noise And Distortion ratio).
On that SINAD Wikipedia…
FriendFX
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7
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3 answers
How replicas are formed in Frequency domain when a signal is sampled in Time Domain?
I know that sampling in one domian (time or frequency) gives raise to replicas in another domain (frequency / time).
How replicas are formed?
What is this Time domain periodicity and frequency domain periodicity here in sampling?
rajez79
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7
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1 answer
Minimization of Essential matrix
A problem in computer vision and 3d reconstruction is getting the camera's intrinsics parameters. A common solution is to use an object in which one knows the measurements of the shape before hand, such as a checker board. The issue with this…
worbel
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7
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Kalman Filter: How to Define Inputs and Outputs of a Model
I'm a software engineer with a CS degree working in machine learning. I'm trying to learn about Kalman Filters.
In this short YouTube video from Mathworks, there's a discussion on a Kalman Filter with regard to a rocket:
We want to measure a rocket…
stackoverflowuser2010
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7
votes
3 answers
Continuous Wavelet Transform vs Discrete Wavelet Transform
The discrete wavelet transform is applied in many areas, such as signal compression, since it is easy to compute. I notice that, However, the continuous wavelet transform (CWT) is also applied to different subjects. In my opinion, the CWT is…
Wang Yun
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7
votes
3 answers
Why does the excitation signal appear, separated, at high quefrencies in the cepstrum?
So, I've just begun a speech and language processing course and have found the explanation of the process of getting the cepstrum of a signal and its properties a little confusing. The following is a description of my current understanding and an…
Sam
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7
votes
1 answer
Estimate and Track the Amplitude, Frequency and Phase of a Sine Signal Using a Kalman Filter
There is sinusoidally controlled signal, which other than being noisy, can change values for amplitude, frequency, phase and offset. At every new sample a new sine is fitted for the last N samples. These fitted signals might be different due to…
user3761419
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7
votes
1 answer
Who first coined "Direct Form I" and "Direct Form II"?
I see "Direct Form I" and "Direct Form II" commonly in literature to refer to FIR / IIR implementation from the filter transfer function, and reference it myself, but where did that terminology first originate so that I can properly credit that…
Dan Boschen
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7
votes
2 answers
Locate Non Homogeneous Areas in an Image
I need to choose some points on an image. These points should be chosen more where there is lots of color changes, transitions and variations. Which techniques can I use for determining where most color changes and transitions occur in an image?
Lyrk
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7
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3 answers
How to Apply the SSIM Measure on RGB Images?
I want to compare the similarity of two images by looking at its structure and colors. I need a measure that takes both structural and color fidelity into account. When I checked the formulation of original paper, it is said only x and y mean and…
Lyrk
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7
votes
3 answers
Is there an adjective describing a filter with kernel that has zero mean?
A linear filter with a kernel that has zero mean could be thought of as a "DC-rejecting" filter. Is there a better or more commonly used adjective for such a filter?
Museful
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7
votes
1 answer
How to calculate critical damping of a system with two springs and a damper (or two springs and two dampers)?
Background
For a simple system where you have a mass attached to a spring and damper in parallel:
We can calculate the critical damping from the equation of motion:
$mx_{tt} + cx_t + kx = 0$
$ms^2 + cs + k = 0$
$s= \frac{-c ±…
mike
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7
votes
1 answer
Circular Convolution as Cyclic Shift Operator
Given the following signal vectors:
$$ γ=[ψ_0,0,ψ_1,0,ψ_2,0,…,ψ_{N-1},0]^T\in \mathbb{R}^{2N}, ϕ=[1,\frac{1}{2},0,…,0,\frac{1}{2}]^T \in \mathbb{R}^{2N}$$
I want to show that the convolution of $γ$ and $ϕ$ is actually a cyclical-shift operator.…
Nave Tseva
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7
votes
3 answers
Applying DFT twice does not actually reverse an array. Instead, the first element stays in place while the rest of the array is reversed. Why?
I've heard a million times that applying DFT twice will result in a reversed array, but that is not what actually happens. Instead, the first element remains where it was, and the rest of the elements are reversed. Is there an intuitive reason for…
PlinyTheElder
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7
votes
2 answers
Increasing SNR and Dynamic Range using Oversampling
How much gain in dynamic range and SNR can be expected if we are to oversample a signal with fixed analog input bandwidth. For Example if I have a analog filter at the input which limits the bandwidth to 100 MHz. The noise power will also be limited…
malik12
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