1. A dimensioning system, comprising: an imager configured to acquire images; a user input/output system configured to display images and to receive user input; and a processor configured to: identify representations of three-dimensional objects in the acquired images; initially select one of the identified objects; display the acquired images and an indication indicative of the initially selected one object via the user input/output system; and computationally determine dimensional data for an object indicated by at least one user input received via the user input/output system.