Restrict access to some images in a public album?

[ciegalo]

Hi to all,
New to CPG, I've been uploading pics for a couple weeks (see link in my profile). The system suits me so well I've installed one for my mother Now I'm looking for a way to restrict access to *some* images in a public album.

Why? Because some of my "travels" albums contain some portraits I do not wish to publish. Setting up 2 albums (1 for neutral, 1 for portraits) is too much trouble and takes the pics out of the context.

Before I stick my nose in PHP and SQL code, has anyone ever looked into that? To obtain this result I'd simply add a field to the image DB (have too look that one up ) that would link to a user group, and modify all the queries (last uploads, favorites, albums...) to restrict access.

I've noticed several questions on the board about allowing an album to be linked with several user groups, I'll look into that too.

Any hints or suggestions ?
Thanks in advance !
Ciegalo