'ius imago': The priviledge of the nobility to preserve wax deathmasks of their ancestors and display them at funerals.
No. According to the review by Stevenson, "there was no formal ius imaginum." As Flower points out in "Ancestor Masks and Aristocratic Power in Roman Culture" (pp. 53-55), the very Latin phrase "ius imaginum" is an an invention of 16th century scholars. In the ancient sources, the closest phrase appears in Cicero, who refers to a ius imaginis ad memoriam posteritatemque prodendae, that is the right of handing over one mask to future generations, NOT the right to preserve such death masks in the first place or to display them at funerals.
To answer the original query, within one's own home, one could display one's own portrait at will. And there are certainly plenty of examples of private portraits to be found, including portraits donated by municipia (e.g., Brutus had a number of these portraits at his Tusculan villa). Of course, putting a statue of oneself in public was not legal, and censors often pulled down unauthorized statues (e.g., Livy 40.51.3). Further, the senate could vote to erect a statue of a magistrate in a public place (typically in a temple precinct).