Computer image processing at Caltech's Jet Propulsion Laboratory (JPL) began over a decade ago with digital processing of single images of the lunar surface returned by the Ranger and Surveyor spacecraft. During the past decade, advanced techniques have been developed at JPL for processing large volumes of imagery returned by the more recent planetary spacecraft, including the Mariner 6, 7, and 9 missions to Mars, the Mariner 10 mission to Venus and Mercury, the Viking Orbiter and Lander Mars missions, and the current Voyager mission to Jupiter and Saturn. In addition, the Image Processing Laboratory (I PL) has become involved in processing of earth resources imagery acquired by the Landsat earth orbital satellite and a variety of other sensors flown on aircraft and spacecraft. The trend within the facility has been toward development of technology capable of processing increasingly larger image data bases. A variety of applications in both the planetary and earth observations areas involve merging and/or processing of more than one image and often require correlation of data acquired by a variety of sensors. This paper describes the evolution that has occurred, and the use of multiple imagery is illustrated through a variety of applications.