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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
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CodeRGV_spectrum_painter
Converting images to IQ streams that make images appear in waterfall plots.
A slightly different concept but to "hide" data in other files (images/audio) is steganography or this cool opensource tool called steghide http://steghide.sourceforge.net/ Interestingly if you do it with audio files, tools like my eXtace (extace.sourceforge.net) (a realtime FFT visualizer for sound) will show it quite clearly in the frequency domain whereas it'll be pretty much invisible in the time domain.
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