[chaps]

Ooh, totally. Many years ago I was doing some analysis of parking ticket data using gnuplot and had it output a chart png per-street. Not great, but worked well to get to the next step of that project of sorting the directory by file size. The most dynamic streets were the largest files by far.

Another way I've used image compression to identify cops that cover their body cameras while recording -- the filesize to length ratio reflects not much activity going on.

[earthscienceman]

Have any more information on the cop camera footage?

[chaps]

Sure -- it's something I figured out during the 2020 protests for some reporting work I was doing which led to this reporting: https://thetriibe.com/2020/12/hundreds-of-chicago-police-mad...

This reporting was made possible because it's surprisingly easy to export recording start/stop time, file size, duration, notes, cop badge and model name from the underlying system with a couple clicks (this is true for any agency that uses axon: https://my.axon.com/s/article/Justice-Exporting-search-resul...). I threw that info into postgres, made a materialized view with a column that gets the filesize:duration ratio and filtered for videos with a certain ratio. I never did anything with it besides that article I posted before.

Here's an observable about the BWC analysis that went into the reporting (disclaimer: the observable is mid-iteration that never received a followup. the analysis itself is separate from the reporting): https://observablehq.com/d/9f09764dbbdfc4b5