Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [background-subtraction]

38 questions
18
votes
5 answers

How can I compare two pictures from the camera and tell if there are enough differences to detect movement?

I want to use my phone as a CCTV system to control a room in my house, and display an alert when something is moving. For now, what I have succeeded in doing is to grab a picture every minute and upload them via a PHP script to my server. Now, I…
Waza_Be
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16
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2 answers

How to extract vocal part from stereo audio signal?

I'm now processing MP3 file and encounter this problem. My MP3 is stereo encoded. What I want to do is extract vocal part for further processing(whatever mode of output signals, mono or stereo are both OK). As far as I know, audio is encoded into…
Summer_More_More_Tea
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8
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3 answers

“Subtracting” one audio stream from another audio stream

I am a long time software engineer but have practically zero experience with signal/audio processing. I am interested in learning about signal processing via a use-case we have for one of our audio components. NOTE: this is just a learning exercise…
CaymanEss
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8
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2 answers

What is the state-of-the-art method for dealing with illumination issues in background subtraction?

I have been struggling to find a well-cited approach to this. Essentially, I am experimenting with different background subtraction algorithms, but none seem to perform well when there are significant lighting changes (say, from a window in the…
charlie
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5
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2 answers

How to Calculate Local Spatial Variance of an Image?

For those who work often on image processing, I'm facing an algorithm of Non-Uniformity Correction (NUC) that requires the calculation of a parameter called "Local Spatial Variance". I can't find a definition for it. Does anyone have any idea about…
tbs1996
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4
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3 answers

Why do we substract a background image and not divide it?

Subtracting a background image for background correction is the standard way of doing background correction to obtain the foreground. I am wondering if there are situations, where it would make sense to divide with the background image instead. For…
packoman
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2 answers

Uneven background subtraction: Rolling ball vs Disk tophat

A classical technique in still images (e.g. fluorescence microscopy images) to remove uneven illumination and isolate bright blobs is to use morphological operation such as the top-hat transform. For instance the Rolling-ball algorithm[1] uses a…
Jean-Yves
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3
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3 answers

segmenting region of interest (ROI) from background

I am dealing with images from biological slides and want to segment out the ROI (cells) from the background. I have tried k-means clustering, otsu thresholding, adaptive thresholding, edge detection etc. Running out of ideas now. Which other…
ankitsingh
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3
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1 answer

How to evaluate a background subtraction algorithm given ground truths?

I'm testing a background subtraction algorithm with sample image sequences. I am wondering how one can evaluate the accuracy of a background subtraction algorithm results given ground truths? The only idea I have in mind right now is to take the…
tnq177
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3
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0 answers

Detecting blades of a wind turbine

I have many close-range images of a single wind turbine blade (taken from different positions, same angle): I need to separate the blade image from background like this: The problem arises in image alignment application where the blade image moves…
Libor
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2
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1 answer

Real time background noise reduction or removal

I am trying to build a real time simple audio recognition that can recognize few keywords. Following this tensor flow tutorial i was able to train a simple neural network. Currently the signal flow looks like this microphone --> Pulse Code…
BhanuKiran
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2
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How to remove a common noise signal from a set of signals?

I have 2D measurement results which seem to have a constant non-trivial background as shown here: For every column in this image, there seems to be a similar oscillation. I'd like to distinguish this oscillation from the real measurement signal,…
physicsPyUser
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3 answers

Background averaging not working

I'm working on a problem where I'm trying to use background averaging to see what the frame looks like in a beehive behind the bees. I've been trying to use standard averaging (I take an image every 1 or 4 seconds over the course of my 3 hour video)…
Jack Simpson
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1 answer

Producing masks from mostly-static-background subtraction when given the background

My data set contains a number of high resolution greyscale images containing a person's face. A single image containing the background without the face is provided. The background is mostly static in the image, except for some minor changes in…
Eustace
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0 answers

Subtracting audio signal emitted - trying to use spectral subtraction to localize moving objects

I am a Software Engineer without much signal processing background and currently spending and experimenting to get use to it. My scenario: Assume a speaker and a microphone array. A speaker emits an ultrasonic sound and the microphone records at the…
Deep Mind
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