Questions tagged [algorithms]
Algorithm is a method expressed in a finite list of steps of well-defined instructions to process a signal.
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Efficient computation of 2^x (antilog2) for fixed-point
I've created a log2 AGC for an FPGA project, similar to Dan Boschen's solution in this question. I implemented a hardware version of log2 based on Dan's linked page in the previous question - ...
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How to Use the Walsh Hadamard Transform to Filter 24 bit RGB Color Values in a Localized Spatial Region?
After reading this Signal processing Stack Exchange article tonight, What Is the Walsh Hadamard Transform? How Could One Use It in Image Processing?, I became interested in applying the Walsh-Hadamard ...
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a moving average relation that I can't find a counter-example to
Hi: I'm new to this list but I had a question that's not exactly related to dsp but maybe in a slight way and I didn't know where else to send it. So, here goes and my apologies if this is totally ...
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Are there algorithms to compare changes in signal amplitudes?
I am working on a project to reduce resonances caused by motors.
The vibrations in the material are measured and sampled by ADCs. The measuring works as intended and the next step is to reduce the ...
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Convolution of signals sampled on a logarithmic grid
Is there a practical accelerated algorithm or a theoretical discrete (Fourier) transform based method to convolve discrete-time signals sampled on a logarithmic grid? What I mean is representing a ...
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Multilateration of Sound in 3D Space
TL:DR - How can you find the 3D coordinates of a emitter than transmits an impulse signal?
STORY:
I'm working on something to improve my bird-watching. I've got a camera that can take pictures of ...
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MUSIC Algorithm for 2D Power Spectrum
I am trying to use Frequency-wavenumber analysis for estimating speed of sound using two-dimensional data obtained via channel of arrays. The traditional technique is to use FFT to transform the data ...
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Extracting 'structure' post permutation
I have particle activity as shown in the left pane of animation below. The activity is clustered and it moves slowly. Sometimes these clusters merges together. On the right side of it, its shuffled ...
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Selection of transforms, windows, wavelets for current signal analysis
I am new to this topic but I already read about the propperties of different signal analysis methods. I am stuck with the obvious advantages of FFT, STFT and Wavelet transforms but can't find good ...
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Digital filter for sharp impulse in data
I am looking for an algorithm or a filter to remove sharp peaks from my data. I am collecting raw data after every 1 second from an sensor through an ADC. The ADC has an internal FIR filter. I use ...
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Career Question: As a person who likes math is signal processing a career that's worth it?
I like high level math and I love deep theory based math.
In industry will I use high level math and theory to implement my own algorithms?
I love high level math but I do not love probability (...
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Obtaining n values from n-1 sensors
As the questions states, lets consider we have 3 gas sensors giving me data for:
A
B
C
Note that only sensors for A and B give absolute values, yet we need the absolute values for all four species:...
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Analyzing accelerometer data: appropriate use of rotation matrices?
I'm working on a project in which a rod is attached at one end to a rotating shaft. So, as the shaft rotates from 0 to ~100 degrees back-and-forth (in the xy plane), so does the rod. I mounted a 3-...
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How to get translation and roation data using 6DOF MPU6150
I am trying to get the position data from an IMU 6 Degrees of Freedom (MPU-6150) board using an Arduino Uno. I am trying Jeff Rowberg’s example MPU6050_DMP6.ino that may be found here.
This is the ...
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Phong Reflection Model Parameters
Question: Can anyone refer me the Phong reflection model parameters for a face image taken for web-cam?
Details:
I am doing 3D reconstruction of 2D images using 3D Morphable Model as in this paper ...
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Are there any signal processing libraries that implement TD-PSOLA?
For such a popular and old algorithm, I've had surprisingly little luck finding implementations. I've got it working in MATLAB, but am curious if any other languages have libraries containing it (...
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--Which dither to use for narrowband speech?
The tl;dr
What dither algorithm should I use when converting 24/48 mono speech to 8/8?
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I'm truncating and downsampling a 24/48 mono audio source containing only speech to 8/8. I won't be doing any ...
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implement gradient descent with sparsification algorithm
I am trying to implement the algorithm in this paper for finding a sparse vector x that minimizes the square error $\lVert y − \Phi x\rVert_2^2$ where $\Phi$ need to satisfy the restricted isometry ...
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Is `fft` always the best choice?
I hope this is the right place to ask this question since it is partially a note which might help others. Until recently, I always used the fft-algorithm ...
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Different kinds of beeps and tones
I have heard many different types of beeps, chimes, and other tones. Audacity allows me to generate simple waveforms like sine waves and square waves, as well as DTMF tones.
But I want to generate ...
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Algorithm for Hue correction behind HSL sliders in image processing software
I have a project where i need to recreate hue specific hue adjustment sliders like in Lightroom/Capture One/DxO photolab.
Initial image.
Image after hue adjustment (Orange hue range) in DxO Photolab....
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Steering Vectors and Bluetooth Low Energy for computing Angle of Arrival
I am new to signal processing, but I have background in mathematics. I am trying to use Bluetooth Low Energy (BLE) on three mobile devices, where one device is being tracked and the other two act as ...
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TDoA self-calibration with a single calibration emitter
I've recently asked a similar question aiming at the same problem on
Math.SE, for which I've set a bounty.
Problem.
I have a radio calibration transmitter with known fixed location $\langle t_x, t_y, ...
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Why some implementation of Wavelet transform use reconstruction filter instead of decomposition filter?
I'm using MODWT (Maximal Overlap DWT) to extract features from a signal. Matlab implementation is using reconstruction filter instead of decomposition filter. In the first level of modwt decomposition,...
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How is the 'difference' of two audio tracks best computed, in order to maximise instrument isolation?
I'm hoping to improve the results of a simple application I've been working on, which aims to isolate as fully as possible the electric guitar heard (along with drums/bass/vocals) on a single track of ...
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Do CQT, FFT, and NNLS provide different "perspectives" on the original signal?
From a bird's-eye perspective, do CQT, FFT, and NNLS algorithms provide different "perspectives" on the original signal? Does each preference some features of the original signal?
I'm using ...
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Removing feature matched outliers within same image using RANSAC
I'm a student working on a copy move forgery detection algorithm.
I have a forged image. By far I have,
Found keypoints and descriptors from the image
Matched the descriptors using 3 Nearest ...
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Dynamic sampling of thermal images
My master’s dissertation subject is to analyze and implement an algorithm that would sample (store) thermal images from camera with different frequency rates to optimize database size and processing ...
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If a function has slowly varying amplitude and phase what is the bandwidth of the amplitude and phase individually?
I am dealing with time histories that are narrow band with slowly varying amplitude and phase. I wish to extract the amplitude and phase but there is noise on the time history. An example of the type ...
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Is my implementation of Generlized Pencil-of-Function correct?
I have a time-series data that should be of the form
$$
f(t) = \sum_nA_n(e^{\alpha_n t}+e^{-\alpha_n(T-t)});\;\alpha_n=\eta_n+i\omega_n;\;i=\sqrt{-1}
$$
and I want to find parameters $A_n$, $\eta_n$, ...
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Asymmetry In The Mirroring Of An FFT Of A Sinusoidal Signal
I am trying to implement a Cooley-Tukey FFT algorithm in its iterative version.
Specifically, I am implementing this Wikipedia pseudocode (please look at the section Data reordering, bit reversal, and ...
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What is the technical term to join two signals with different phases?
there is a name for this:
If I have two signals with a discontinuity, arrange the phases of one signal to fit the other and not see the discontinuity.
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Space-Time coding uses large amount of block codes to acheive maximum spectral efficiency
Assume I have a MIMO system with $M=8$ transmit antennas, and an arbitrary number of receive antennas.
This MIMO systems uses space-time coding. the block codes (matrices) transmitted are part of a ...
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Robust peak detection taylored for spectroscopy
i need a algorithm for peak detection in raman spectroscopy. I tried this one, but it did not give me satisfying results.
Spectrums may look like this:
In professional software, i think they use the ...
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Determine 3 most dominant frequencies in a signal, PSD or just the absolute value of a Fourier transform?
I have a noisy ECG signal recorded for 5 minutes. My goal is to determine heart rate every 2 seconds. To find out 3 most dominant heart rates (Beats per minute) in a 2s-signal should I calculate its ...
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Improve NMF for data with partial overlaps in multiple groups?
I want to use NMF to separate true sources from data. My data is in group structure with overlap elements. For example (in the smaller version)
group1: contains A,B,C,D,E,F,G patterns
group2: ...
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Message-round probability in SCCC graph
I am reading the paper Interleaver Design for Serial Concatenated
Convolutional Codes by Yu et al., and it states the concept of message-round probability as $F(l_1)F(l_2)$ where $F(l)$ refers to the ...
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Horn Schnuck Optical Flow Algorithm's Formula
In the below pic, I can not understand what U vector is? It says flow field but I can not imagie what really is the flow field?
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Dot or point pattern recognition for Braille Paper
we are very new to image processing field.
We are gonna do a study about braille to text conversion, by the way braille is a method of writing for blind.
!(https://fryemuseum.org/images/...
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Frequency identification as a convex problem
Suppose I have two time series, $x(t)$ and $y(t)$: $x$ is the output of a sine wave generator, and $y$ is the generator's frequency setting. Given a training set of $(x, y)$ pairs, Is it possible to ...
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Efficient computation of Chirp Z Transform
Chirp Z Transform (1, 2, 3) is more powerful than zooming techniques (I use it to actually trace non-stationary chirp signals) and very usable in signal processing, but it's flexibility comes at price ...
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Estimating the power consumption of an arbitrary, real-time DSP algorithm
Consider a digital signal processing algorithm that operates over a block of $L$ [samples], with a real-time constraint $\tau$ [s] (i.e. its throughput must be $L/\tau$ [samples/s]).
The theoretical ...
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Algorithm to identify periodic signal spikes
I'm working with a special chip that allows me to record current draw on phones. This chip logs data with its internal timestamps.
I now need to generate a unique signal that will allow me to map the ...
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How to generate Gray codes of n bits that have at max k ones?
I understand Gray codes have one bit change between them and how to convert between binary and gray. But given a bit length of n, I want to generate a series of Gray codes (all possible) that have one ...
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Fingerprint minutiae matching
I am working in a fingerprint recognition project using C code running on embedded system. After processing the fingerprint image, I have the minutiae now. I tried to matching two sets of minutiae by ...
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Low dimensional system identification algorithms
I'm a physics Phd student and just have a self-taught knowledge about lti-systems. After a while I found out that several techniques such as heat capacity or thermal-conductance measurements can be ...
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The relationship between zero level set and thickness information
I have one problem that need you help. I am try to find the relationship between active contour and thickness information. For defination of thickness we can find at thickness measuring and active ...
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select meaningful part out of a signal (for goertzel)
I have an on going input signal, most of the time with no activity.
Once in a while there is an activity (oscillations in different freq).
I need to take good 205 samples out of the signal.
what i ...
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Are there any lossless embedding algorithm to support Haar(DWT) in audio watermarking?
I've been trying to do some research on audio watermarking and what i wanted is to insert string into audio file in the transform domain (DWT), i've read some literature of DWT especially HAAR ...
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Image Recognition Benchmarks
I was wondering if anyone knew anywhere I can obtain benchmark comparison of various algorithms used for similarity recognition. In my research I found one study from 2008 or so, but misplaced the URL....
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