Human in Photo?

April 13th 2021

I shot a timelapse of Sarah binding her thesis. I used the timelapse system described in a previous post. I was left with about 12,000 frames, but only some of them had Sarah actually doing work in them.

I needed to build a timelapse of Sarah working. I tried several libraries that look for human shapes in photos, but they ended up being, inaccurate, slow, or overly complicated.

I had tested out Imagga for an unrelated tagging project a few years back, and it looks like at some point in the interim they added some face detection tools. With a basic account you get 1000 API calls per month, and after some testing it looked like Imagga would be fast and easy to use.

This passes an image to Imagga asking it to find a human, and then just counts the number of characters in the returned data. The data is pretty short if there’s no humans, and it’s longer if there is a human.