This is my Gallery Site - I have created my own gallery scripts and Macro's - as no Confluence Plugins supports images in a filestructure.
Requirements
Software
Atlassian CLI (Notice the 3.X versions are not free, last free download versions at Atlassian CLI
Imagick and ffmpegthumbnailer installed, this can typically be done with a package manager for the OS.
Scripts
Script for making thumbnail images (makethumbs.sh)
Script for importing images into a Confluence page (updateGallery.sh)
User Macros
User Macro: make-top (User Macro)
User Macro: go-top (User Macro)
User Macro: me-image - Image lightbox with Slimbox2 (User Macro)
User Macro: include-lightbox - Slimbox2 including (In Custom HTML or Layout)
User Macro: me-video - Linking to a Video file (User Macro)