Questions tagged [noise]
Noise is random variation in a signal, for example errors in measurements of the position of a moving object.
noise
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Random / noise functions for GLSL
As the GPU driver vendors don't usually bother to implement noiseX in GLSL, I'm looking for a "graphics randomization swiss army knife" utility function set, preferably optimised to use within GPU ...
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How to use Kalman filter in Python for location data?
[EDIT]
The answer by @Claudio gives me a really good tip on how to filter out outliers. I do want to start using a Kalman filter on my data though. So I changed the example data below so that it has ...
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votes
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answers
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mouse position to isometric tile including height
Struggeling translating the position of the mouse to the location of the tiles in my grid. When it's all flat, the math looks like this:
this.position.x = Math.floor(((pos.y - 240) / 24) + ((pos.x - ...
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votes
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answers
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First random number after setSeed in Java always similar
To give some context, I have been writing a basic Perlin noise implementation in Java, and when it came to implementing seeding, I had encountered a bug that I couldn't explain.
In order to generate ...
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How can I make a Pink Noise generator?
((Answer selected - see Edit 5 below.))
I need to write a simple pink-noise generator in C#. The problem is, I've never done any audio work before, so I don't know how to interact with the sound card,...
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Simulating TV noise
I have googled a bit but was never able to find an answer. What should be my first approach to simulate a video and audio noise from TV on screen? I mean, when my TV antenna is removed but the TV is ...
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Play simple beep with python without external library
Using only the modules that come with a standard python 2.6 installation, would it be possible to play a simple beeping noise?
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Noise Estimation / Noise Measurement in Image
I want to estimate the noise in an image.
Let's assume the model of an Image + White Noise.
Now I want to estimate the Noise Variance.
My method is to calculate the Local Variance (3*3 up to 21*21 ...
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Defining a white noise process in Python
I need to draw samples from a white noise process in order to implement a particular integral numerically.
How do I generate this with Python (i.e., numpy, scipy, etc.)?
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Why does simplex noise seem to have *more* artifacts than classic Perlin noise?
I read Stefan Gustavson's excellent paper on simplex noise, in which I was promised that:
Simplex noise has no noticeable directional artifacts
in contrast with "classic" Perlin noise. I excitedly ...
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Fastest Perlin-Like 3D noise algorithm?
It's been well over 20 years since Ken Perlin first invented his noise. Has anybody managed to make a faster kind of 3D noise generator with properties close to Perlin's (procedural, natural-looking ...
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Any Simplex Noise Tutorials or Resources? [closed]
I want to create a terrain-like 3D noise generator and after doing some research I came to the conclusion that Simplex Noise is by far the best type of noise to do this.
I find the name quite ...
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Good way to procedurally generate a "blob" graphic in 2D
I'm looking to create a "blob" in a computationally fast manner. A blob here is defined as a collection of pixels that could be any shape, but all connected. Examples:
.ooo....
..oooo..
....oo.....
- 10.2k
19
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1
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Adding gaussian noise to a dataset of floating points and save it (python)
I'm working on classification problem where i need to add different levels of gaussian noise to my dataset and do classification experiments until my ML algorithms can't classify the dataset.
...
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2
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How can I measure image noise
I've found a few ways of reducing noise from image, but my task is to measure it.
So I am interested in algorithm that will give me some number, noise rating. That with that number I will be able to ...
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votes
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Reducing noise on Data
I have 2 lists with data points in them.
x = ["bunch of data points"]
y = ["bunch of data points"]
I've generated a graph using matplotlib in python
import matplotlib.pyplot as plt
plt.plot(x, y, ...
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2D Perlin Noise
I have fully mastered the art of Perlin Noise in 3D, and now I'm trying to use my same implementation for a 2D algorithm.
The problem seems to be in picking my gradient directions. In 3D I use 16 ...
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votes
1
answer
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Using PyKalman on Raw Acceleration Data to Calculate Position
This is my first question on Stackoverflow, so I apologize if I word it poorly. I am writing code to take raw acceleration data from an IMU and then integrate it to update the position of an object. ...
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2
answers
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Removing pattern and noise in an image using FFT in matlab
I am using the clown.jpg image to be able to get rid of the obvious pattern/noise it has.
The first step that I did before taking FFT of the image is to rescale it a square image of powers of two (...
16
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Determine frequency from signal data in MATLAB
I have data from a sensor and I need to find the frequency of it. It looks like fft() seems to be the way to go, but the MATLAB docs only show how to get a graph of the frequencies, I don't know what ...
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In need of Fractional Brownian Noise (FBM) vs Perlin Noise clarification
I'm researching the various types of noise for terrain generation and I'm a little confused regarding when noise becomes perlin noise and when perlin noise becomes fbm. I'm hoping somebody could ...
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Adding noise to numpy array
So say I'm trying to create a 100-sample dataset that follows a certain line, maybe 2x+2. And I want the values on my X-axis to range from 0-1000. To do this, I use the following.
X = np.random....
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How to Calibrate Android Accelerometer & Reduce Noise, Eliminate Gravity
So, I've been struggling with this problem for some time, and haven't had any luck tapping the wisdom of the internets and related SO posts on the subject.
I am writing an Android app that uses the ...
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4
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Proper way to add noise to signal
In many areas I have found that while adding noise, we mention some specification like zero mean and variance. I need to add AWGN, colored noise, uniform noise of varying SNR in Db. The following code ...
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4
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How to generate noise in frequency range with numpy?
I have a main signal, for example sinus with period of 200 samples.
I would like to add a noise to this signal. The periods of "noise signal parts" should be in range for example 5-30 samples.
I ...
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2
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Active Noise Cancellation through default iPhone headphone
We want to create an App that will implement the Active Noise Cancellation using the default iPhone headphone. That is, to receive the external audio using the iPhone headphone Mic and make a phase ...
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2
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Detecting noise via mic while playing a song on iPhone
I am making an app that should play a simple audio track and let me know if there is any noise in the vicinity while the track is playing. This is done by doing a live recording from the microphone ...
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2
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Wrote some perlin noise kind of code, it looks blocky
The previous answered question doesn't seem to answer my problem "Blocky" Perlin noise
I tried to simplify the most I could to make my code readable and understandable.
I don't use the ...
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FFmpeg transcoding on Lambda results in unusable (static) audio
I'd like to move towards serverless for audio transcoding routines in AWS. I've been trying to setup a Lambda function to do just that; execute a static FFmpeg binary and re-upload the resulting audio ...
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Per-Vertex Normals from perlin noise?
I'm generating terrain in Opengl geometry shader and am having trouble calculating normals for lighting. I'm generating the terrain dynamically each frame with a perlin noise function implemented in ...
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3
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Generating 3D noise quickly in python
I need a method to generate 3D simplex noise in python rather quickly. What methods are there out there to solve this problem?
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How to simulate pink noise in R
I know that white noise can be achieved by treating the output of rnorm() as a timeseries. Any suggestions on how to simulate pink noise?
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Generating colors of noise in Java
I would like to create a colored noise generator using Java that will be able to generate all of the colors defined in this article: http://en.wikipedia.org/wiki/Colors_of_noise
Starting with the ...
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Do Keras dropout and GaussianNoise layers apply different instances of noise in every batch?
I am building a denoising autoencoder in Keras. The model I'm using is
input_img = Input(shape=(10,))
encoded = GaussianNoise(0.01)(input_img)
encoded = Dropout(0.1)(encoded)
encoded = Dense(20,...
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Perlin Noise in Java
For a cellular automata project I'm working on I need to generate two dimensional boolean arrays randomly using different algorithms and techniques. At the moment I have just one type of randomization ...
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R: How to generate a noisy sine function
I am still pretty new to the whole R-thing.
I have the following aim; I have a sine function that describes a calcium particle number over time:
something like y = a * sin (b*t) + c
Since in reality ...
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Are there any other uses for Perlin Noise besides the obvious?
I have been looking into different algorithms lately and have read quite alot about perlin noise. It seems like the only thing people use it for is to generate textures (clouds/wood grain) or to ...
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How to plot blurred points in Matplotlib
As the question says, I'm looking for a way to plot blurred points using Matplotlib.
I don't want to plot a set of points and then apply a filter to blurry the whole image. Instead of it, I would ...
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Using imnoise to add gaussian noise to an image
How do I add white Gaussian noise with SNR=5dB to an image using imnoise?
I know that the syntax is:
J = imnoise(I,type,parameters)
and:
SNR = 10log10[var(image)/var(error image)]
How do I use ...
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Software sound cancelling (destructive interference) tools on Linux? [closed]
I am looking at writing some software that will allow me to listen to music whilst talking with someone on skype. The problem is that if you do this with speakers the music also gets transferred to ...
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FFTW: signal consists of noise after IFFT
After doing FFT and IFFT I can hear only noise in my headphones... Here is the code:
double* spectrum = new double[n];
fftw_plan plan;
plan = fftw_plan_r2r_1d(n, data, ...
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Query noise level in Android
I want to develop a small Android app to measure the current noise level (probablyin dB). But I have no idea what to look for in the libs. I don't want to record the noise. Can someone give me a ...
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Adding poisson noise to an image
I have some images that I need to add incremental amounts of Poisson noise to in order to more thoroughly analyze them. I know you can do this in MATLAB, but how do you go about doing it in Python? ...
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How to add Gaussian noise to an image?
How to add a certain amount of Gaussian noise to the image in python? Do I need to convert somehow the values of the image to double type or something else?
Also, I have doubts about measuring the ...
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atmospheric noise and generating random numbers java
I was interested in finding out how one can use atmospheric noise to generate true random numbers. I know RANDOM.ORG does it but they (of course) don't explain what the process is and how it can be ...
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5
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Random noise for GAN
I am new to GAN. I am learning to model GAN to generate images,however I don't really understand what exactly is the random noise given to the generator. Is it random numbers from 0 to 1 and what ...
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Why is my Monte Carlo Raytracing so noisy?
I have implemented global illumination using the Monte Carlo method, using the scratch a pixel tutorial as a guide. My final image renders very noisy! The example below is at 64 samples, I have ...
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Infinite Blue Noise
I am looking for an algorithm which produces a point placement result similar to blue noise.
However, it needs to work for an infinite plane. Where a bounding box is given, and it returns the ...
7
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1
answer
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Image deblurring on Matlab
Im new to MatLab. Been playing around and reading through the help guide but i can't seem to solve this situation.
I have removed the noise by using gaussian algorithm. That was successful but I've ...
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How can I remove noise from this video sequence?
Hello I am trying to do some image processing. I use Microsoft Kinect to detect humans on a room. I get depth data, do some background subtraction work and end up with a video sequence like this when ...
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