add_image_size for post type

Question

I currently have this in my functions file, which works as expected:

// Enable Post Thumbnails
add_theme_support('post-thumbnails');
// Custom Thumbnail Sizes
add_image_size( 'square-small-thumb', 80, 80 );
add_image_size( 'square-medium-thumb', 150, 150 );
// Guide image sizes
add_image_size( 'guide-gallerythumb', 142, 85 );

However as it's a large site i'm working on with various post types I don't want my assets folder to be cluttered with too many unused images, therefor I'd like to have some 'global' image sizes but then some image sizes specific to post types, is this possible?

For example, I'd like

add_image_size( 'square-small-thumb', 80, 80 );

To only be generated for the post type 'news'

Answer 1

I had this issue before, and this answer by Jan Fabry was of use, hope it works for u guy!

Answer 2

I don't know how is your site, but I think is a waste to add a 80x80 thumb if you have a 150x150, you can use the 150x150 and scale it down with css.

But beside that, maybe there is someway to limit the file creation only to post types.

Maybe something related to a question I just did: New image size version only for the Featured Image file