Add dots to an image

Add dots to an image

I need to let a web page user add small dots to an existing image, at locations of the user's choice.

Is this capability already out there?

To express it differently: The page contains a standard image of a car. The user puts red dots on the car to indicate the locations he's observed scratches or dents. We save the marked-up image by merging the dots with the image and saving it to a new name (or more likley creating dots at the user-supplied dot coordinates). The merging is back-end work, and can be done with many simple tools, I'm not asking about the back-end here.

What I seek is a plugin to permit the user to click on the image to place the red dots. I don't want heavy drawing tool, just click to place pre-defined dot.

If you can't think of a similar plugin, I wouldn't say no to suggestions for how to proceed.