Many moons ago I was using this software which would screenshot every five seconds and give you a little time lapse and the end of the day. So you could see how you were spending your computer time.

My hard disk ended up filling up with tens of gigabytes of screenshots.

I lowered the quality. I lowered the resolution, but this only delayed the inevitable.

One day I was looking through the folder and I noticed well almost all the image data on almost all of these screenshots is identical.

What if I created some sort of algorithm which would allow me to preserve only the changes?

I spent embarrassingly long thinking about this before realizing that I had begun to reinvent video compression!

So I just wrote a ffmpeg one-liner and got like 98% disk usage reduction :)