Image and image gallery technical specifications

Some technical details on images and the image gallery:

New version of this article:
http://www.janroe.com/node/149

The following it outdated:
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Backdrop:
Drupal v6.13

Modules:
- image
- access control (acl, needed for forum access and image gallery access)
- image gallery access (image_gallery_access)
- custom pagers (to add previous-next buttons to image sets)

Setting permissions (acl, image_gallery_access)
- in the global permissions ui
- in the image creation/edit ui

Note for important addons not yet added:
- flash gallery (flash_gallery)
- galleria is also nice but handbook complicated