To import a georeferenced Nearmap image into Global Mapper:
In Global Mapper, from the File menu, select Open Data File.
Navigate to the folder containing both the Nearmap image you downloaded, and its corresponding .jgw file. Select the Nearmap image.
In the Select Projection... window, select options corresponding to the projection you downloaded your imagery in. This example uses NAD83 UTM Zone 12 (EPSG 26912).
The Nearmap image loads and displays in Global Mapper.