Defining the output mosaic

After you add the source images you want to use, your next step is to enter information about the output file—the mosaic—to create, which includes the following:

Create the mosaic as a single file, tiled, or as defined by polygons
Name and format
Number of channels, and the mapping of each
NoData value in the mosaic
Resampling method
Extents of the mosaic
Size of the mosaic
Pixel size (x and y)
Applicable Earth model and whether to use datum or ellipsoid in the reprojection
Bounds and the coordinates thereof

Note: If you remove one or more images (not all), the extents are resized automatically. You can, if necessary, generate the mosaic preview, and then go back and add or remove additional images. The extents will, again, be resized automatically. However, if you make changes to the mosaic-definition settings or generate the output mosaic, you must manually resize the extents.