For raster mosaics, you can create a composite mosaic to update one part of an image with new imagery. This is useful when, for instance, a particular region of an aerial photo mosaic needs to be updated because of building development or other geographic changes but an entire new image set is not needed. By updating just the affected image tiles geospatial image users can keep pace with geographic changes without constantly acquiring new image data for every region.
To update an image, create a new raster mosaic and select the composite mosaic option.
NOTE: Updating an image or set of images results in a flattened mosaic if flattening is specified by the user or if tiles of differing resolutions are used.