This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Purple noise spectrum. Spectrum analysis of Purple noise ogg seconds of purple noise Analysis done using Audacity plotting with GnuPlot Violet noise spectrum svg Instructions Obtain the frequency analysis from Audacity set the maximum number of windows and use Hamming window The following script was used to generate the image