Watermark on the picture on the fly?

Question

PHP

Good evening colleagues. The task is as follows: there are 700+ thousand links to images not on our server. They need to insert our watermark. It seems not a problem to download them and put down signs, but the problem is that all these images need to be updated once a week. I came up with the idea to put a watermark on the fly, i.e. do not download pictures, but when you want to display a picture, then substitute it. Help make this happen. Thank you.

Answer 1

The idea is so-so. At the same time, 20 people will visit the site - and you will have to process hundreds of pictures on the fly. It is unlikely that this will be done in parallel in 100 threads. You will queue tasks. And the pictures will appear in the browsers of visitors with a noticeable delay.
It is necessary, apparently, to keep the entire database of images with a watermark on your server. And constantly drive the process, slowly updating pictures in one thread, preferring the most not updated for a long time.