Image:Blue noise spectrum.png

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[edit] Summary

Spectrum analysis of 10 seconds of blue noise (help·info).

Analysis done using Audacity, plotting with GnuPlot

[edit] Instructions

Obtain the frequency analysis from Audacity, set the maximum number of windows, and use a Hamming window. The following script was used to generate the image:

set terminal png transparent font "/usr/share/fonts/truetype/ttf-bitstream-vera/Vera.ttf" size 800,600 enhanced
set output "blue_noise_spectrum.png"

# this seems to fix the trailers on the TTF font for the x-label
set bmargin 4

# enable grid
set grid
set grid mxtics

# set up x-axis
set logscale x 10
set xrange [100:22000]
set xlabel "Frequency (Hz)"
set xtics border nomirror

# set up y-axis
set yrange [-40:0]
set ylabel "Intensity (dB)"
set ytics border nomirror

# again to deal with bad bboxes on the TTF...
set key height 1 box

# plot the output from Audacity
plot "blue_noise.txt" title "Blue Noise" with filledcurves x1 3

[edit] Licensing

I, the creator of this work, hereby release it into the public domain. This applies worldwide.
In case this is not legally possible,
I grant any entity the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

File history

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• (del) (cur) 02:02, 14 March 2006 . . Ktims (Talk | contribs) . . 800×600 (5,076 bytes) (Spectrum analysis of {{Audio|Blue noise.ogg|10 seconds of blue noise}}. Analysis done using Audacity, plotting with GnuPlot)

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• Colors of noise