Code for generating 1/f^alpha pink noise

Started by Sampo Niskanen in comp.dsp9 years ago 12 replies

Hi, In a recent project I required a source of 1/f^(5/3) pink noise, but was unable to find any code or explanation on how to perform that. ...

Hi, In a recent project I required a source of 1/f^(5/3) pink noise, but was unable to find any code or explanation on how to perform that. The DSP Generation of Pink Noise page[1] contains extensive information on generating 1/f pink noise, but has no mention of 1/f^alpha pink noise. I therefore made my own code for the purpose. It produces pink noise by filtering white noise with...


Kalman Filters and Pink Noise

Started by Tim Wescott in comp.dsp5 years ago 4 replies

Oddball question. Or maybe just a plea for comments. I'm kind of getting painted into a corner, and the color of the paint is pink. It's...

Oddball question. Or maybe just a plea for comments. I'm kind of getting painted into a corner, and the color of the paint is pink. It's looking like I need to estimate pink noise with a Kalman filter. Anyone done anything remotely like this? Know of anyone who has? Did they survive? The method that I know of for simulating pink noise involves running white noise through a fil...


pink noise

Started by sham...@gmail.com in comp.dsp10 years ago

How can identify pink noise statistically, as we identify that this signal is speech and this is noise, because using autocorrelation and...

How can identify pink noise statistically, as we identify that this signal is speech and this is noise, because using autocorrelation and harmonics analysis leads to pink noise identified as signal.


Acoustic memory

Started by Robert Adams in comp.dsp10 years ago 3 replies

I accidentally discovered something interesting, and thought I would share it here. Prepare a sound file with the following sequence of...

I accidentally discovered something interesting, and thought I would share it here. Prepare a sound file with the following sequence of events. 1) Pink noise, 10 seconds 2) Filtered Pink noise with several notches in the frequency response (moderate Q's, frequencies in the 200Hz to 5KHz range), 10 seconds 3) Pink noise (no filtering), 10 seconds You would think that 1) and 3) woul...


pink noise

Started by Karl in comp.dsp13 years ago 4 replies

Hi ALL I need an algorithm to generate pink noise (a drop of 20dB/decade) from white noise (use in simulink) that is suitable for a frequency...

Hi ALL I need an algorithm to generate pink noise (a drop of 20dB/decade) from white noise (use in simulink) that is suitable for a frequency range of 1 to 100 Hz. Any suggestion is appreciated. Regards Karl


Generate Pink Noise Efficiently

Started by Robert Scott in comp.dsp5 years ago 41 replies

I am looking for a compute-efficient algorithm to generate pink noise. The application must run on a smartphone (iPhone or Android w/NDK)...

I am looking for a compute-efficient algorithm to generate pink noise. The application must run on a smartphone (iPhone or Android w/NDK) and take up a small fraction of the available compute time. The application has other compute-intensive real-time tasks that cannot be bogged down by this noise-generating task. The purpose of the pink noise is to serve as an analog indicator of a measure...


Why do RTA DEQs use pink noise?

Started by Impoliticus in comp.dsp13 years ago 3 replies

I'm working on a project for a DSP lab class and as you may have guessed from the topic, the project involves programming a real time analyzer...

I'm working on a project for a DSP lab class and as you may have guessed from the topic, the project involves programming a real time analyzer DEQ. Perhaps I should have asked this in the planning/research stage, but why do RTA equalizers, such as the DEQ2496, flatten the frequency response of the loudspeakers with respect to pink noise? I understand that pink noise has equal energy per octave, b...


Blue Noise creation via filtering?

Started by No Name in comp.dsp13 years ago 24 replies

Hello all, I trust I'm not intruding. I'm interested in creating "blue noise", as referred to in the following "Colors of Noise FAQ" posted in...

Hello all, I trust I'm not intruding. I'm interested in creating "blue noise", as referred to in the following "Colors of Noise FAQ" posted in comp.dsp, and other sources: http://tinyurl.com/45h2k A quick synopsis: "blue noise" is so named because the power is concentrated at the high end of the spectrum. It has a power distribution of P = f, vs. P = 1/f for pink noise. Pink noise,...


pre-made bitstream, pink noise with only one RC filter?

Started by Anonymous in comp.dsp11 years ago 5 replies

Is there a way to generate a bit stream, and output it directly to a single stage simple RC filter, and the output be pink noise up to...

Is there a way to generate a bit stream, and output it directly to a single stage simple RC filter, and the output be pink noise up to some cutoff, say 20khz? This would seem to be a very easy, cheap, simple way to make a pink noise generator. I assume you cant output the square-wave bitstream directly to a transducer (speaker, etc..) since it will contain the dominant switching frequency, (r...


Comfort Noise Generator

Started by kanhaiya in comp.dsp13 years ago 3 replies

Dear Experts Well I've read a few previous posts on this aspect. The documents or references I used were: RTP Payload for Comfort Noise...

Dear Experts Well I've read a few previous posts on this aspect. The documents or references I used were: RTP Payload for Comfort Noise RFC3389. Appendix II of G.711 Annex B of G.729 Well my query is regarding implementation of a codec independent CNG: 1) Which excitation is best for this CN (white or pink)? 2) I tried with only noise energy level transmission, and generating pink...


Thresholds for white/pink noise ...

Started by Anonymous in comp.dsp11 years ago

Hi, I took a signal processing module years ago but w/o useful labs :(. I am in the process to do some experimentations. Unfortunately, i...

Hi, I took a signal processing module years ago but w/o useful labs :(. I am in the process to do some experimentations. Unfortunately, i don't have the practical knowledge to take some decisions. In particular, i am interested to know from what a threshold value i should consider a signal being a white noise or pink noise. I have drawn the spectral distribution of a signal. despite bei...


Filtering out pink & white noise

Started by Francois Maillet in comp.dsp12 years ago 1 reply

Hi, I'm trying to filter out heavy white and pink noise in a wav file to figure out the frequency of a repeating piano note. I'm kind of a...

Hi, I'm trying to filter out heavy white and pink noise in a wav file to figure out the frequency of a repeating piano note. I'm kind of a noob. I'm working with Matlab and I'm just not to sure what kind of filter I should use... If anyone could give me any brief ideas I'd greatly apreciate it. Thanks in advance, Frank


Filtering out pink & white noise

Started by Francois Maillet in comp.dsp12 years ago

Hi, I'm trying to filter out heavy white and pink noise in a wav file to figure out the frequency of a repeating piano note. I'm kind of a...

Hi, I'm trying to filter out heavy white and pink noise in a wav file to figure out the frequency of a repeating piano note. I'm kind of a noob. I'm working with Matlab and I'm just not to sure what kind of filter I should use... If anyone could give me any brief ideas I'd greatly apreciate it. Thanks in advance, Frank


is this pinking filter literal?

Started by Anonymous in comp.dsp11 years ago 4 replies

I'm trying to generate pink noise from a bunch of 8 bit random numbers, and I came across this: b0 = 0.99765 * b0 + white * 0.0990460; b1...

I'm trying to generate pink noise from a bunch of 8 bit random numbers, and I came across this: b0 = 0.99765 * b0 + white * 0.0990460; b1 = 0.96300 * b1 + white * 0.2965164; b2 = 0.57000 * b2 + white * 1.0526913; tmp = b0 + b1 + b2 + white * 0.1848; from http://www.firstpr.com.au/dsp/pink-noise/#Filtering Is this some kind of special code that runs it matlab, where b0, b...


Generation of Pink Noise using 3dB/octave filters on digital white noise

Started by bademiya in comp.dsp11 years ago 23 replies

Hi guys. I want to know how is it possible to generate digital white noise in a ADSP-BF561 board? I have tried searching for algorithms on...

Hi guys. I want to know how is it possible to generate digital white noise in a ADSP-BF561 board? I have tried searching for algorithms on digital white noise generation but i have been getting a lot of variations on the algorithms and the source codes. My intention is to generate digital white noise and use 3dB/octave filters to make the output into a digital pink noise. This output will th...


Generating 1/f^2 and 1/f^3 noise

Started by Marc Brooker in comp.dsp11 years ago 25 replies

Hello, I am currently writing software to generate 1/f, 1/f^2 and 1/f^3 noise for use in a simulation, using an existing Gaussian PRNG....

Hello, I am currently writing software to generate 1/f, 1/f^2 and 1/f^3 noise for use in a simulation, using an existing Gaussian PRNG. Currently, I am generating 1/f noise with the Voss-McCartney algorithm (from here: http://www.firstpr.com.au/dsp/pink-noise/), and it seems to work extremely well and perform well enough for my application. I am generating the 1/f^2 noise (noise with...


Generating 1/f (flicker/pink) noise

Started by Anonymous in comp.dsp8 years ago 32 replies

Dear All After having spent a frustrating hour searching around to find some simple code that would generate 1/f noise, or more generally...

Dear All After having spent a frustrating hour searching around to find some simple code that would generate 1/f noise, or more generally 1/f^alpha noise, I decided to write it myself. So here goes: http://www.eng.ox.ac.uk/samp/powernoise_soft.html I hope you enjoy it. Comments and feedback welcome. All the best, Max


Removing White Noise

Started by Duane in comp.dsp12 years ago 13 replies

Hey everyone, I have an audio application, and I'm trying to do some pre/post processing to improve the sound quality. I put in an adaptive...

Hey everyone, I have an audio application, and I'm trying to do some pre/post processing to improve the sound quality. I put in an adaptive filter to try and remove structured noise, but I'd like to remove white/pink noise from the signal somehow.. I've been looking at wavelet techniques, or whatever else I can find. Can anyone recommend a good way to reduce white noise from audio/ A...


Interpreting noise

Started by Anonymous in comp.dsp12 years ago 10 replies

How do I know the difference between a signal which is decreasing in power as frequency increases because of its characteristic...

How do I know the difference between a signal which is decreasing in power as frequency increases because of its characteristic distribution (e.g., pink noise, brown noise), and a signal which is decreasing in power as frequency increases because it's band limited (e.g., white noise with a continuous falloff)? Thanks, Trevor


Time domain representation of colored noise

Started by Prateek B S in comp.dsp5 years ago 9 replies

I understand that the time domain representation of white noise looks like impulses. How do colored noises like brown, pink etc. look like when we...

I understand that the time domain representation of white noise looks like impulses. How do colored noises like brown, pink etc. look like when we perform an inverse Fourier Transform on them ? What could be some sources of colored noise that may affect speech signals? I am currently working on a project that involved removing noise from speech signals. Any help would be greatly app