Is there any web service to generate unique images?

Question

HTML

Hello!
We have in the projectfor key entities (user, group, meetup), a fairly rich visual design (background images, thumbnails) is assumed. Naturally, there are a large number of users who do not want to deal with design, and therefore a lot of boring / monotonous placeholder images appear on the site. I would like to generate unique images for such cases using a separate service. Something like you give him the dimensions, id of the pattern generator of the image, (and, perhaps, some value for initialization, for example, hash id of the entity + image type), he will give you an image, without preludes :). I'm sure you've seen generated images like this in avatar thumbnails on github.com, or stackoverflow.com, I want something like this for a custom image size.
Important! This is not about a collage of thematic illustrations, but about the fact that the service could really "draw" a new image according to some algorithm, even if not very complicated - a couple, three lines of several colored areas, for example.
Questions:
In which direction should you look? ;)
Maybe there is already a ready-made open source solution that fully or partially implements the described functionality?
What libraries / plugins for js, ruby, php (your favorite PL) would you recommend to implement such a service?

Answer 1

Don't forget about:
https://placekitten.com/ - cats
https://randomuser.me/
uifaces.com

Answer 2

Lots of beautiful photos. You can get immediately in blur, bw, different sizes.
https://unsplash.it/
And to draw... I don't know

Answer 3

For users, you can use gravatar . There are unique pictures by default + the user himself can upload his avatar once. Many large projects use them, including github

Answer 4

Try this .

Answer 5

There is also imgholder.ru , you can’t draw an arbitrary abstraction, but you can change the size, background color, text color and add your own text without problems.
More or less like this:

Answer 6

look at lorempixel.com