Questions tagged [detection]
The detection tag has no usage guidance.
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Primitive Feature Detection to Detect a Black Circle within an Image
I am trying to check whether this black circle is exist or not on my images.
My current approach is like that;
Hough Circle detection
Crop the outer roi
Adaptive threshold
count zero pixels
if ...
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frame size and hop size mismatch with aubio pitch detection algo
I am writing a script that detects the pitch of a short file as part of a larger project. I want to detect using an external call to sox and using the crepe, aubio, and librosa libraries. Aubio is ...
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Probability of Detection and pulse-pulse decorrelation time
I'm trying to analyze the probability of detection ($P_d$) for a Swerling II target. I know that the Swerling II target assumes that the Radar Cross Section (RCS) is an exponential probability density ...
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MIMO detection using ZF and MMSE
I have a problem related to my uni assignment. The task seems rather simple - plot SER as a function of Es/N0 for 2x2 MIMO and 16-QAM modulation assuming AWGN noise and Rayleigh flat-fading channel. ...
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Annotate a dataset of images
I'll be recording a new dataset using a couple of sensors: kinect, stereovision cameras.. for a project for people detection using only depth information.
But I don't know yet how can I annotate the ...
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Detection problem with extra noise observation. Does the extra observations help with detection?
Assuming all “real” number, consider the detection problem of $x$ given $y_1$ and $y_2$ below
$y_1= x + n_1$
$y_2= n_1 + n_2$
where $x$ is either $+A$ or $-A$ with equal probability, and $n_1$ and $...
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Reed-Solomon: a combination of error correction and detection in the CD CIRC algorithm
It's well known that, with 4 redundant symbols, a Reed-Solomon decoder can either correct 2 incorrect or detect 4 incorrect symbols. In "The Compact Disc Digital Audio System: Modulation and ...
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Symbols to samples at the transmitter and samples to symbols at the receiver
Suppose I have the $N\times 1$ vector $\mathbf{x}$ that contains binary phase shift keying (BPSK) symbols each with power $P_s$ Watts.
At the transmitter: I want to convert these symbols into samples ...
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Lung Detection and Segmentation in X Ray Image
I'm a beginner in image processing and I have to create a segmentation algorithm to detect lungs from an image .
Image given :
And after removing the noise from the image and applying a threshold the ...
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detect what is noise in audio signal
I'm trying to filter noise from an audio signal. The signal was and is going to be recorded in a city environment which always contains some white/pink noise.
At this moment I'm using two options to ...
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Efficient Marker Detection for Images
I need to detect a known number of simple markers (chessboard patterns) in a color image efficiently.
I implemented normalized cross correlation (NCC) as a pixel shader via WebGL since I need this to ...
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MIMO Radar - Using statistical properties of the Fourier transform phase for detection
I currently researching the phase (between real and imaginary part) of the fourier transformation. It seems that one can use it for detection.
For the signal processing I use two fft transforms. One ...
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What Is the Best Color Space to Work with for Hand Detection: RGB, HSV, or YCrCb?
I'm working on hand gesture recognition using C#. I'm using OPENCV for skin detection but its performance is not optimal. So I decided to do some filtering based on color space, but I do not know what ...
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Interpolating Filter for Quadrature Detector with one ADC
Single ADC is sampling at 16000 Hz the I and Q outputs of quadrature detector. So each I and Q signal is sampled at 8000 Hz, with phase offset 90 degrees between them. Bandwidth of interest is 3400 Hz....
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AWGN continous time channel + colored noise
I'm working on an exercise but I'm stuck at the question where the noise becomes colored, can someone help me ?
Let $\{\psi_1(t) = \mathbf{1}\{t \in [0,1)], \psi_2 = \mathbf{1}\{t \in [1,2]\}\}$ be an ...
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What is the type of each 4 different noise signals that are shown below?
I am looking at four different noise signals. I got them in a time domain and they are different. I went to the frequency domain and found the fft for all four ...
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Slicing an Image into Tiles According to Content
Given an image that contains an NxM grid of icons with text below them, somewhat like this:
I'm wondering how to split it up into the individual icons with text. Some wrinkles:
The image won't ...
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Questions about minimum detectable RF signal level
I would like to estimate the ideal minimum detectable power levels for a few different tuners. I am wondering the best way to go about doing this just by using well-known engineering equations along ...
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Does flat surface detection and orientation require special hardware to compute?
Modern augmented reality platforms such as Google's ARCore and Apple's ARKit seem to only operate on mobile devices, I'm guessing, because their underlying algorithms require specialized hardware that ...
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Why does my PLL simulation oscillate after locking?
I'm working on a crude circuit simulator with the goal of implementing PAL encoding and decoding, so that I can experiment with generating images that look like video transmissions.
In the simulation ...
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Trim syllable audio recording to only the vowel
For a Chinese learning app, we let users record a syllable and we use speech recognition to assess if the pronunciation was correct or not.
Every Chinese syllable can be pronounced with different ...
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Find gaussian in data
I have some time series data (blue line lower plot) with a gaussian added into it (red line upper plot). I would like to estimate where the gaussian is in the data, and the height of the gaussian (...
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Detect a Frequency Change in a Step Wise Frequency Chirp
I am driving a system with a step-wise frequency chirp from 50-400 hz with a frequency step of 0.01 hz. I am having difficulty identifying the points of frequency change as the data collected has an ...
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How do I measure the amount of information within an image?
I'm trying to find some information threshold that is required for performing detection of objects in images. However, I'm not sure how exactly to quantify the amount of information contained within ...
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How to detect the presence one- and two-dimensional patterns in distributions of spatial points?
I have many point patterns, and I want to detect those patterns that have points arranged in lines that may be curved, intersected or broken. For example, on the following picture, the upper left ...
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mathematical expression to detect modulated data within a vector
Assume I have such modulated data which is, for example, $x=0.7+0.7i$. That modulated data is encapsulated in a vector as below:
OR
where $c$ is any constant number, let’s say, for example: $c=0.7$ ...
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What is the difference between object detection and target detection? Are they the same thing?
I was reading some articles regarding object detection and target detection and have a hard time understanding the difference between object detection and target detection. i want to know whether they ...
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where we use estimation and detection in communication system?
I read from the book that we use estimation when we are dealing with analog signal or continuous random variable and the term detection when the transmitted signal is a discrete value even if a ...
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pitch detection: which is the most robust way to distinguish voiced from unvoiced audio
I am trying to write a voice/whistle driven synth but I am struggling with pitch detection. As a premise I must say I am quite skilled and experienced at dsp coding plus I have pretty read almost ...
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Maximally Stable Extremal Regions (MSER) Implementation in Document Image Character Patch Identification
My task is to identify character patches within the document image. Consider the image below:
Based from the paper titled "CG-DIQA: No-reference Document Image Quality Assessment Based on ...
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CFAR Detectors and Interference
Constant False Alarm Rate (CFAR) is an automatic thresholding technique. It's situated after the FFT processing in other to detect target peak. This probability of detection depends on clutter and ...
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Projecting a vector to another to detect the sparse values of such vector
Assuming we have sparse vector of length $N$ such as $X = [0,1,0,-1,0,1,1,0]$ which has some non-zeros values. The vector $x = iFFT(X)$ is convoluted with another vector $h$ resluting $y = h*x$. ...
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Detect low power DSSS-BPSK signal
I have heard that it is possible to detect a low power (ie not visible on a spectrum analyzer) DSSS-BPSK (direct sequence spread spectrum) signal even when you don't know the spreading code by ...
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Absolute value based AM envelope detection viewed in the frequency domain
In my understanding when a passband AM signal is demodulated with an envelope detector taking the absolute value restores the original baseband version of the signal and the low-pass filter removes ...
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lock in detection based denoising using matlab?
What are the limitations of implementing the lock in detection technique in matlab?
I have time varying data with known frequency with huge background noise. The reference signal is also available. ...
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Face Recognition: Simplistic Explanation on PCA Eigenface Algorithm
I m working on a project that I have to use eigenface but I have some uncertainty and I dont know how to deal with it. There are some tutorials about it on internet but I can't understand what exactly ...
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Synchronize device to audio stream - Approach
I am working on a device which's actions should be synchronized to the audio played. The audio stream is known in beforehand and can be altered to contain signals for the synchronization. But the ...
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Radar signal processing flow chart
I'm new to Radar in general, and I'm studying RADAR using online resources. I came across the following slide which shows the process flow of the Radar signal processing.
The thing I don't get in ...
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Detection of a Circle in Noisy Image Data
I have an image that looks like the one below:
I'm trying to find the radius (or diameter) of the circle.
I have tried using circular Hough transform (via matlab's ...
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Should I Use a High Pass Filter (HPF) or Low Pass Filter (LPF) to Enhance the Features for Image Splicing Detection?
I'm recently learning image splicing detection. I've already known image splicing can bring some abrupt changes to an image,which generate the sharp edges.And sharp edges correspond to high frequency. ...
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How detect signal from noise?
I'm trying to detect when a signal is "on" from samples I have. Those samples come from a software defined radio, if that matters, and the signal i'm trying to detect is a WiFi signal.
The problem is ...
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Generating a colored waveform of an audio file?
I would like to ask on what approaches could one attempt to generate a colored waveform out of an audio file. Below are two examples of waveform coloring by commercial products along an audio sample ...
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Threshold for CAF Surface
I am calculating a time partitioned Cross Ambiguity Function (CAF) by adding the surfaces of different time-sectioned CAFs together. Meaning, I calculate a CAF using 10 seconds of IQ data, calculate a ...
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How to set sigmas and kernels for 3D-Laplacian of Gaussian filters to blob detection in Matlab?
I have written code according to a paper for Lung CT images, but its output wasn't correct. I think it is because of the setting of its parameters.
The paper is about a multi-scale method using a ...
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Note Recognition Software
I'm wondering if anyone knows of any open source solutions to note recognition. I'm planning on building a program for online sheet music, which recognizes your notes, and tries to tell you what you ...
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Voice masking for removing voice and not birdsong
First the problem I'm tyring to solve:
I'd like to find a way of removing any potential noise from audio files recorded in noisy environments where we are trying to record birdsong. This is for the ...
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finding frequency range and dominant frequency of a stored signal
I have sEMG signals, captured from commercially available device. the signals are stored in .tdms file format. i want to varify whether the captured signals are really sEMG (or simply EMG) signals or ...
CommunityBot
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Ship detection from aerial image
I have an aerial image, like this
I want to detect the outline of the ship without shadow. How can I do it? I tried threshold in both graylevel, RGB and HSV. It doesn't work perfectly.
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non linear equalizer vs linear equalizer
i understand that there are linear equalizers such as MMSE and ZF, however there are also non-linear equalizers such as MLD. i would like to know what is the difference between a non-linear equalizer ...
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An alternative algorithm for blob detection
Here's a sample image of my experiment which is to be processed for finding the information of all the blobs (centre, dimension etc.). Basically the image contains some noise, few bold lines, and of ...
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