Questions tagged [algorithms]

Algorithm is a method expressed in a finite list of steps of well-defined instructions to process a signal.

83 questions with no upvoted or accepted answers
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92 views

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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77 views

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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156 views

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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35 views

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 ...
2
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1answer
69 views

Are there any efficient algorithm to detect circular shape of arbitrary size in an image?

I have images that are 1278 by 1024. They are pictures of a certain product that is rectangular in shape and are about 25mm by 20mm. As a part of a quality inspection process using computer vision, ...
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80 views

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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173 views

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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177 views

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 (...
2
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1answer
2k views

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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85 views

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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910 views

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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92 views

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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110 views

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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32 views

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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40 views

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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25 views

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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38 views

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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33 views

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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113 views

Why does the griffin lim algorithm work?

the griffin lim algorithm works to reconstruct audio from a magnitude spectrogram, but i don't understand how reusing the same spectrogram every iteration with noise can produce decent sound How from ...
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167 views

Is there a FFT algorithm which is both in-place and constant geometry?

I work in crypto where the NTT (Number Theoretical Transform) which is just a FFT in finite fields is used. I wanted to know if there exists an implementation of the FFT which is both in-place and ...
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1answer
165 views

Separation of signals without loss of information about the signals themselves

There is a signal that contains: Rectangular pulses on frequency of 1 kHz Rectangular pulses on frequency of 1.4 kHz Other noises. Required: Separate 1kHz pulses from everything else and measure ...
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76 views

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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110 views

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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66 views

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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24 views

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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35 views

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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861 views

Radix-8 butterfly with Winograd and Cooley-Tukey algorithm

I saw the Winograd radix-8 kernel algorithm below, shown in the image. Comparing to the mathematical formula of Cooley-Tukey, there is a multiplication by $\cos$ and $\sin(\pi/8)$, which can't be ...
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88 views

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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273 views

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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66 views

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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68 views

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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72 views

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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814 views

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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1k views

GCC-PHAT cross correlation

I am trying to implement GCC-PHAT in python. The approach is similar to the following two links: link1 and link2 It seems the only difference between GCC-PHAT and normal cross-correlation using FFT ...
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52 views

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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59 views

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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37 views

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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164 views

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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88 views

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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319 views

Complex Demodulation (CDM) and Fixed Frequency Complex Demodulation (FFCDM)

I do not quite understand the difference between the CDM and FFCDM. How can I implement CDM in a program?
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60 views

Dividing a data set into segments with consistent inner behavior, using segmentation algorithms and metrics for consistency

Context of the problem: I have signal data which was recorded in a software system and which shows the runtime of multiple processes over time. In total there are more than 900 processes each having ...
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9 views

Efficient Method to match vector time series where the vector entries may not line up

Asking here because I couldn’t find or didn’t have the right words to search for the answers online. Also sorry for no examples—gotta maintain my NDA for work. I have two N-dimensional vector time ...
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5 views

Active noise control in LabVIEW using cRIO (FPGA and real-time module)

Has anyone tried to implement the example code in LabVIEW for active noise control usin the my CRIO controller? I have an experimental setup of two microphones (primary and error microphone) and two ...
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7 views

Processing accelerometer and gyroscope data

I'm working on an instrumented headform to measure linear and rotation acceleration of the on impact, for which I'm using ADXL377 accelerometer and ICM-20649 angular rate sensor. What kind of ...
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65 views

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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1answer
64 views

How do I implement a footstep recognition algorithm? One that recognizes the start and end points of each footstep?

I have some time series data captured from a person's footsteps/strides (specifically, a person on rollerblades). It came from an IMU sensor placed on a person's boot. Each data point captures ...
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22 views

Bilinear Interpolation Algorithm for up-sampling 2D images

In keras it is possible to use UpSampling2D layer to up-sample an image. You can use Bilinear Interpolation. Given an image ${h\times w}$ it is possible to increase its size in ${h*k\times w*l}$, ...
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23 views

image processing, edge enhancement

*Hello I used k mean method to detect edges and that’s my results as shown in the pic but I want to get more accurate results so I need to enhance my edge detection more what methods would you suggest ...
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58 views

How can I implement a phase detection algorithm with my amplitude detection?

I have been recently working on a signal detection problem in Matlab. At the minute I am detecting signals based on their amplitude, using an m-of-n detector. I am interested in improving the false ...
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34 views

DFT algorithm designed for a "sample-by-sample" senario

Suppose I have a system that wants to take an input signal (audio in this case) and wants to output a Discrete Fourier Transform of it in real time (ie every sample). My initial thought is that if you ...