GIS and IGE file formats are used to store raster/bitmap graphics from ERDASIMAGINE geospatial data authoring software and if any software can help you convert one or vice versa, it would be this software. We have not found any specific information about such gis to ige conversion or export, but it is likely that resave is doable. Just keep in mind that .gis files are gray-scale and the same will apply to newly saved .ige files.
Updated: August 21, 2023