Closure, an actual psychology term relating to filling in information? I'm currently reading a book called "Understand Comics" and a term has come up called closure. I've understood this concept before and the book describes closure as the process the brain goes through to fill in the missing information to formulate some conclusion. 

To give a little more detail, the books describes it as observing the parts, but perceiving the whole. Everything that we perceive about the world is through our senses, but most of the time our senses can only reveal a world that is incomplete or fragmented so we depend on this idea of closure to draw conclusions. 

Is this process called closure in the psychology?
The more common psychological and probably everyday use of the term closure refers to a desire  for information that may resolve an issue or situation (e.g., see closure psychology).

I think that the form of closure you describe comes from the Gestalt school of psychology. To quote the wikipedia article on Gestalt Psychology regarding Law of closure:


  The law of closure states that individuals perceive
  objects such as shapes, letters, pictures, etc., as being whole when
  they are not complete. Specifically, when parts of a whole picture are
  missing, our perception fills in the visual gap. Research has shown
  that the purpose of completing a regular figure that is not perceived
  through sensation is in order to increase the regularity of
  surrounding stimuli. For example, the figure depicting the law of
  closure portrays what we perceive to be a circle on the left side of
  the image and a square on the right side of the image. However, there
  are gaps missing from the shapes. If the law of closure did not exist,
  the image would depict an assortment of different lines with different
  lengths, rotations and curvatures, but with the law of closure, we
  perceptually combine the lines into whole shapes.


More generally, what you describe on is touched on by a number of psychological theories covering different phenomena. For example, there is filling-in describing the process by which visual perception is filled-in over the physiological blind spot and scomata.

Furthermore, most models of cognition would construe perception as the interaction of external stimuli, our cognitive architecture, and existing representations. For example, if you look at job satisfaction data, responses are often as much a function of the individual as they are of the work environment. Or to take another example, models of learning suggest that whether a stimuli is perceived as a threat depends on our prior experience with the stimuli.  

It seems that the book that you are reading is extending the perceptual idea of closure to incorporate a broader cognitive component.