Alternative 1: Use database and open with Colmap  Alternative 2: code https://nbviewer.org/github/cvg/Hierarchical-Localization/blob/master/pipeline_Aachen.ipynb https://nbviewer.org/github/cvg/Hierarchical-Localization/blob/master/pipeline_InLoc.ipynb 
Alternative 1: Use database and open with Colmap

Alternative 2: code

https://nbviewer.org/github/cvg/Hierarchical-Localization/blob/master/pipeline_Aachen.ipynb
https://nbviewer.org/github/cvg/Hierarchical-Localization/blob/master/pipeline_InLoc.ipynb