Questions tagged [software-implementation]

Questions related to implementation of various algorithms under software environments and programming languages.

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How to specify the cut-off frequence in cascaded biquad filters?

As part of my effort to understand how a high-pass filter can be implemented, I'm reading this section of HandWiki. My question here is: How do the 2 simple formula presented there filter out at a cut-...
DannyNiu's user avatar
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1 answer
67 views

Understanding how to implement high-pass filter with cascaded biquad filters

I'm trying to understand how to implement a high-pass filter using, quote: a cascasded biquad direct form II IIR filter with a cut-off of 8kHz. DSP is a complete new field for me, and the ...
DannyNiu's user avatar
  • 125
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20 views

How to use an LDPC encoder implemented in C in MATLAB and which (open source) encoder is most energy-efficient?

I am looking for an open source LDPC encoder available online as I just have to use it for encoding raw bits to LDPC-encoded data to estimate the energy consumption. Which is the best encoder from the ...
Anamika's user avatar
1 vote
0 answers
37 views

Is there an open source "Data over Voice" library?

I need to transfer data from A to B using audio as the medium, with a speaker at one end and a microphone at the other. Sometimes simply through the air, but it must also work through legacy phone ...
Björn Morén's user avatar
1 vote
0 answers
51 views

PyWavelets CWT : error when differentiating after convolution?

I'm trying to understand the implementation of CWT in PYWT. This topic has already helped me quite a lot but there is still a thing that is unclear to me : why is the result differentiated only after ...
Tanguy Jonv's user avatar
1 vote
0 answers
48 views

DSP library for Software Defined Radio

Can anyone recommend a good C library for SDR? To be more specific I just need a function in C to compute coefficients for CIC compensation filter (I need to do it in real time, so Matlab is not an ...
dcs's user avatar
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1 vote
1 answer
76 views

Handling asynchronous MCU I/O peripherals

Technical Background I'm making an audio processing board with an onboard microcontroller that takes in data via I2S from an ADC, applies digital filters, and outputs a stream of the same samplerate ...
theseventhsu's user avatar
1 vote
1 answer
87 views

Implementation of dispersion compensation of lamb waves

I am trying to implement the method from Paul Wilcox paper "A rapid signal processing technique to remove the effect of dispersion from guided wave signals" on data from a lamb wave ...
vegiv's user avatar
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1 vote
0 answers
167 views

Is it feasible to implement analog-style spectrum analyzer and sliding DFT as visualizations in music players?

The real-time constant-Q transform are possible using sliding DFT (sDFT) because unlike FFT, sDFT can have arbitrary frequency scale and variable per-bin window size, and of course, the realtime CQT ...
TF3RDL's user avatar
  • 11
2 votes
0 answers
44 views

Implementing digital controller in the time domain

I have simulated a digital control system in the Z domain using MATLAB and I have got satisfactory results. However, when I converted the plant and the digital controller to difference equations and ...
learn design's user avatar
0 votes
1 answer
593 views

Constellation Mapping In OFDM

If i am not mistaken, the two following hold : a. In OFDM Conceptualization, the constellation mapping at Tx (or de-mapping at Rx) is done in Frequency domain b. However the basic theory (Including ...
Vinayak Anant Karandikar's user avatar
0 votes
1 answer
666 views

Voice activity detection (VAD) libraries 2023

I am trying to use (not implement VAD algorithm) voice activity detection to get timestamps for a given audio but facing hard time doing so. What I am trying to achieve ? Find an offline library for ...
Gangadhar Jannu's user avatar
1 vote
0 answers
98 views

Audio smooth / enhance algorithm, software

Years ago I was working with a sound editor program called Sony Sound Forge. It had this filter of smooth/enhance which I liked and used a lot, but now I can't find such filter in Adobe Audition or ...
user174174's user avatar
1 vote
1 answer
165 views

How many directions are there in the Non Maximum Suppression part of the Canny Edge Detector

In the Non-maximum suppression algorithm, each pixel has a total of 4 directions since there are 8 neighboring pixels. But why there is not 8 directions instead, please? I see below there are 8 ...
Avv's user avatar
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0 votes
0 answers
256 views

Implement Quinn’s second estimator for frequency estimation

I am trying to get the estimation frequency from the FFT output in unity, I have read that Quinn's second estimator method is the most accurate method, and I found the algorithm for how to implement ...
WhiteNight's user avatar
2 votes
1 answer
170 views

Implementation of Deriche filter

The Canny edge detector is expressed by the derivative of the Gaussian. Its practical implementation involves the Gaussian filter, then the Sobel filter to calculate the gradient in both directions. ...
edgeboyy's user avatar
2 votes
1 answer
96 views

Apply 2D Convolution on an Image Using Tiles

I have 2D convolution with a large input image (512x1920). I am trying to partition the image across height and width to perform this convolution as N pieces. This would involve having an intersection ...
AcidBurn's user avatar
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2 votes
0 answers
32 views

Implementation boundary-corrected wavelets on the unit interval

I was wondering if there is a 'ready-to-use' implementation available of the (boundary-corrected) wavelets constructed in Cohen, Albert, Ingrid Daubechies, and Pierre Vial. "Wavelets on the ...
Brazilian Cérebro's user avatar
3 votes
3 answers
664 views

Modeling Analog Filters for Software Implementation

I am curious about software implementation of analog filters. For example, let's say I have a moog low pass filter. What should I do to turn this device into satisfactory, analog sounding software. I ...
someoneunimportant's user avatar
-1 votes
1 answer
435 views

Modelling and testing fixed point IIR filter with freeware tools

I understand from this other question that prior to implementing a fixed point IIR filter on a particular microcontroller target it's best to create a model using a DSP tool and compare the output to ...
davegravy's user avatar
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1 vote
1 answer
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Transposed direct form 1 vs Transposed direct form 2

I am studying IIR filters and their implementation. I am following the material published by Julius Orion Smith at Stanford. In particular, I am reading this page at the moment. It explains all the ...
Mattia Surricchio's user avatar
5 votes
1 answer
758 views

Replicate MATLAB's `conv2()` in Frequency Domain

When conv2d is on same mode, the image needs no padding, because the result is the same size as the image. When ...
Mage Front's user avatar
0 votes
1 answer
903 views

IIR implementation - RuntimeWarning: overflow encountered in double_scalars [closed]

I have implemented a butter filter in python using this function: ...
Rariusz's user avatar
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3 votes
1 answer
1k views

Image Convolution Using DFT (FFT)

I just can't get my head around Fourier transform and convolution in 2D. I am trying to implement image convolution using fast Fourier transform (in julia). So the first thing I need to do is to pad ...
Avec's user avatar
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1 vote
3 answers
216 views

Simulating room impulse response between rooms

I want to simulate a sound source in one room and a microphone in a second, adjacent room. I am familiar with the image method and Habet's very efficient implementation for room impulse response (RIR)....
havakok's user avatar
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1 vote
0 answers
84 views

ORB Implementation, Scale Pyramid, rFAST

Reading this ("ORB: An efficient alternative to SIFT or SURF") paper, I am not certain how they use the scale pyramid. It says it is created and FAST feature detectors are employed at every ...
Darian Dzirko's user avatar
4 votes
2 answers
641 views

Efficient implementation of rolling MAD/Hampel filter

I have implemented the moving median absolute deviation (moving MAD) and it seems like bit-exact to Matlab's implementation. Nevertheless, I am sure that it is not efficient. The usual median filter ...
Gideon Genadi Kogan's user avatar
1 vote
0 answers
885 views

Implementation of Cepstrum in Python

Actually I want to denoise a signal. I know how can I implement FFT in python to denoise it. This is the implementation which I use(From this Kaggle notebook): But I don't know : How can I use ...
Vahid Shams's user avatar
0 votes
1 answer
637 views

Speech recognition algorithm in GNU Octave to convert speech to text (and vice versa)

Recently, I am building an application in Octave and I saw some algorithms about speech recognition spread around the net, but most of them were implemented in Python, MATLAB, C++ and no one in Octave....
theEarlyRiser's user avatar
1 vote
2 answers
253 views

How to use Octave ellip() coefficients for 3-band C++ crossover

I have been working on making a 3-band audio crossover in C++, with the goal of activating/deactivating a different device depending on whether the low, mid, or high range of the input is above a ...
silentTeee's user avatar
2 votes
2 answers
157 views

Feedforward disturbance signal compensation

The reference Feedforward control concepts through Interactive Tools says, to minimise the effect of the disturbance $d$ on the process output $y$, a compensator $G_{\text{ff}}=P_3/P_1$ shall be used. ...
mikebuba's user avatar
1 vote
1 answer
394 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 ...
Partha's user avatar
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3 votes
2 answers
166 views

How to Design a Model based on Convolutional Neural Network (CNN) which Supports Arbitrary Input Size in Training and Production

I'm doing a research about personality identification based on their signature using CNN method, however the learning feature for the personality traits have a different input size. I understand that ...
Smurf Again's user avatar
3 votes
1 answer
64 views

Simple Binary Image Classification (Person / No Person) in `C`

i have to do a project for university which is basically to program a tool to classify small greyscale images like those below into person or non-person, in C. The project is scheduled for around ...
stackexchanger1's user avatar
2 votes
1 answer
54 views

How to calculate linear index of fuzziness of an image?

i am trying to calculate linear index of fuzziness of an image using this formula: i have to see a positive value according to the paper. But i see a negative value, so i think i am doing something ...
beyblade41's user avatar
1 vote
0 answers
160 views

I can't implement plateau limit histogram equalization algorithm using MATLAB

i tried to implement this research paper using MATLAB. Unfortunately, my result is not same with the original result. Here is my try step by step: ...
beyblade41's user avatar
2 votes
2 answers
1k views

What is the impulse response used in an interpolation filter when upsampling?

I need to downsample a single period waveform from $M$ samples to $L$ samples. If that matters, in my particular case, $L=M-1$. I read about downsampling and came to the conclusion I need: expand ...
Sylvain Leroux's user avatar
7 votes
1 answer
677 views

Which Noise Reduction Algorithms Are Used in Commercial RAW Image Processors?

I'm trying to guess what noise reduction algorithms are used in commercial processors for raw images from digital cameras. I find this fairly easy to do for the sharpening algorithms (most use unsharp ...
Potato's user avatar
  • 123
1 vote
2 answers
177 views

Where can I find information about how to implement IIR filters on micro-controllers?

I am trying to implement an IIR filter on a LPC1769 (I don't know if it's relevant). I already have the H(z) so all the design part is prety much solved. What I am looking for is information about: ...
Gaston's user avatar
  • 21
1 vote
1 answer
99 views

bibliography about implementation of IIR filters

I need to implement a 6th order IIR filter. The filter I need to implement is the A-weighting. I've simply used the bilinear function of Matlab with an fs of 20Khz. I need to implement this over the ...
Gaston's user avatar
  • 21
2 votes
1 answer
419 views

Implementation of a Separable Bilateral Filter for Edge Preserving Smoothing

I’m trying to optimize my naively implemented O(n^2) bilateral filter for 2D images. I googled and found a lot of theoretical explanations about the separate one. However, it seems there are things ...
jinglei's user avatar
  • 121
0 votes
0 answers
107 views

books on audio processing open source projects and software

Because I would like to understand how open source projects work and give my contribution improve my programming skills and understand better and implement algorithms in a real project I'm looking ...
Francesco Boi's user avatar
0 votes
0 answers
91 views

Scipy Welch's gives different first element

I've re-implemented Welch's method and want to compare it to scipy.signal.welch. However, the first two and last elements of the resulting array are different. My ...
skjerns's user avatar
  • 101
1 vote
1 answer
265 views

FM synthesis algorithm is not very efficient

I have very little knowledge of DSP, I'm trying to implement an FM synthesis algorithm in code / software. So far I've successfully implemented a FM algorithm using the following: ...
Chris Stryczynski's user avatar
0 votes
1 answer
920 views

Isosurfaces from three dimensional column data: methods

I have just been asked the following question, and I somehow felt short of smart answers. You are given a series of $N$ triplets of values ($P_1$, $P_2$, $P_3$), pertaining to physical measurements. ...
Laurent Duval's user avatar
3 votes
1 answer
1k views

Compute group delay of an audio file from STFT

I'd like to reproduce results from this paper in which the authors used Group Delay-grams as an input to the Machine Learning model. The Machine Learning side is not the one that I have problems with. ...
Colonder's user avatar
  • 143
0 votes
1 answer
173 views

Synchronize a software waveform generator

I'm having some trouble with a software waveform generator I'm attempting to put together. Especially with synchronizing the waveform. Goal Generate a mains synchronized (50 Hz) sinusoidal waveform ...
Jeroen3's user avatar
  • 103
4 votes
2 answers
8k views

Fastest Available Algorithm to Blur an Image (Low Pass Filter)

I am working with a camera that produces ugly artifacts: by using ANY blur filter on the camera's output the visual quality improves drastically: The above image was created using OpenCV's cv::...
Crigges's user avatar
  • 145
0 votes
0 answers
174 views

How to build a software audio mixer - low level approach [duplicate]

my questions might come across different SE forums. But here it is. A little context : I'm currently building a midi sequencer, the architecture is this way (for now) I've got a ARM v7 + a PIC, the ...
YCN-'s user avatar
  • 121
7 votes
5 answers
567 views

Curve Fit of Step Function with Boundary on the 2nd Derivative

Consider this step function: The signal that "fits" this should look like the following (in green): The corners are now smooth because the maximum second derivative allowed is not infinite anymore. ...
Juan Molina Riddell's user avatar