Calibrating multiple monitor or projector display elements to provide a composite image can be a time-consuming task if performed manually. Ideally the user would like to roughly aim a number of projectors at a surface, define the desired display corners, and have some automatic method to align the display. A digital camera and computer vision can be used to calibrate the projectors with the assistance of self-identifying patterns. To account for distortion effects and to equalize brightness, it is desirable to know the mapping of many points within each projector image. A small set of images can be projected from each display element if a self-identifying pattern is used. An array of ARTag markers are used as a self-identifying pattern which is displayed in turn by each of the display monitors or projectors and recognized in the camera image. In this way an ad-hoc arrangement of projectors can be calibrated in seconds. Experimental results are shown validating this architecture.