The system provides different ways for users to select an object and an action to be applied to the object in computer applications such as image processing or digital post-production. The user can select an object first and then an action, or vice versa. The user can also use gestural input to designate both an object and action virtually simultaneously. Multiple view, or windows, of an image can be independently sized, zoomed, panned, etc. Any effects performed on the image appear in all of the windows since each window shows (potentially) different portions of the same image content. A navigation window helps a user move within a large image or diagram that does not fit entirely on a single display screen. The navigation window includes an inner box that shows, in miniature, the principal objects in the screen display.