Call an related action from an link in interface

Technically a related action is just a process model that you could start using a!startProcessLink. Would that fit your use case?

You can just call the model in the image save into, which is used for related action by passing the required parameters, 

Agreed with Stefan.  To clarify, you'll need to make a choice between an actual Related Action, versus just calling a process model using Start Process Link.  Related Actions (specifically) can only be invoked from Record Actions which are limited in terms of what UI elements can be used, whereas a Start Process Link can use any link style (but can't use some of the Related Action specific stuff like opening in a pop-up dialog, unfortunately).

Yes, use a startProcessLink to execute your process — after all, even a related action executes a process.