If your camera (or phone) uses the DCF standard [0], you will eventually end up with duplicates when you hit IMG_9999.JPG and it loops around to IMG_0001.JPG. Filename alone is an unreliable indicator.

[0]: https://en.wikipedia.org/wiki/Design_rule_for_Camera_File_sy...

> loops around to IMG_0001

Almost all cameras create a new directory, e.g. DSC002, and start from IMG_0001 to prevent collision.

Which systems still use this shortsighted convention? All photos I’ve taken with the default camera app in the last many years are named with a timestamp.