Tutorial 14: Add a Timestamp to your Picture
Okay this tutorial isn't specific to just the Raspberry Pi. Any Linux machine can do this. In this tutorial I show you how to install Image Magick on your Raspberry Pi and use the software via Bash commands (in Python 3) to append a time stamp to the pictures you take with the Pi Camera.
This tool allows you to append any text to the images you want. I am doing a time and date stamp. You could also apply this to situations where you keep track of other values such as temperature, speed, position, whatever is relevant to your project.
This tutorial is a little older (published in 2015!). The main principles are still relevant, so I haven't needed to update this lesson.