I want to publish my imagery to portal for arcgis 10.4.1 to use it as basemap instead of esri basemap , my imagery is 70 GB .
How can i achieve that ??
Publish it to local ArcGIS Server (with Image extension) and add this service into webMap.
Save the WebMap as basemap.
Then assign it to the basemaps group.
Here are some other (older) threads/links that discuss using custom base maps: