It is not just the imprinting which is a problem.
Baby birds are taught so many survival things by their parents to ensure they can survive and thrive- they are taught what they can safely eat, how to eat alone, what trees are best to use for shelter and nesting, where to find foods, what is and is not to be trusted, what can be eaten to help some ailments, a language special to that species (and sometimes a particular flock) only etc.
Humans who raise baby birds and release them once they are eating on their own basically send the bird out die after raising them. Rehabbers raise them in a specialised way if they are to be released or do a very lengthy slow release that is supported in a way that will ensure their survival.
If you release this baby once fledged and weaned, with how young it was when you first shared a pic, it will die very soon after being released- either starvation, trusting the wrong other living beings, having no clue how to protect itself from the elements, not knowing bird etiquette etc Many vets and wildlife workers here will tell people to let nature take its course with birds such as sparrows, starlings, mynahs etc as it seems extra cruel to save a baby now only to condemn it in a few weeks time after it has become dependant on humans and all the comforts we provide.
My suggestion would be to get yourself a nice cage for your new family member