Using GDAL from the command line to create the following:

1. A 2% image preview of the mosaic composed by 64 .JPEGs images. First a preview file is created with "gdalbuildvrt" and then from this file we create the 2% image preview showned, with the command "gdal.translate". This is useful to do some QA before continuing to create the bigger raster with all the 64 files.

2. Create a Tile Index of the mosaic with the command "gdaltindex" This index is a .shp file. Is useful when working with large amounts of imagery to locate a specific tiles and to catalog raster data.

   Project from Mastering GDAL course