1. A machine-implemented method, comprising: storing change information about visual changes that occur in a two-dimensional view of visual information; causing a user interface to be displayed that allows a user to specify search criteria; wherein one search criteria option that the user interface allows the user to specify is a scope-of-change indication; wherein the user interface presents controls for selecting between (1) a first scope-of-change option that indicates that a visual change must occur anywhere within a specified region of interest and (2) a second scope-of-change option that indicates that a visual change must occur across the entire specified region of interest; receiving, from the user through the user interface, first search criteria that specifies: a first region of interest within the view, a particular visual change, and a scope-of-change indication that indicates one of the first scope-of-change option or the second scope-of-change option for said particular visual change; and comparing the first search criteria against said change information to identify a sequence of frames, within the visual information, (a) in which said particular visual change occurred within said first region of interest and (b) that satisfy the scope-of-change indication; wherein the method is performed by one or more computing devices.