Stop image resizing in particular case - is that possible?

Question

As for an ad management plugin, I'm using WordPress' default media uploader. And WP Media Uploader automatically resizes images. But as the ad image is already resized (i.e.: 225 x 100px) it need not to resize into a new file for thumbnail (100 x 100px); because, that thumbnail is unnecessary for the site.

The cause I presented here, may be a very minute for such a solution, but in case, there is any other massive issue that, in such plugin we can stop the auto resizing with WP Media Uploader only on that plugin-uploads - I think that can be a good solution for any site.

Is there a way to use WP Media Uploader, but can stop auto resizing images only onto that particular case uploads?

But I also know that, plugin like Regenerate Thumbnails can override the rules and can do what I prohibited in my plugins for the site's space-savvy consumption.

Answer 1

Use the Filter Hook intermediate_image_sizes_advanced for control the resize function for different sizes. This hook get a array of different sizes and can control your resize with your requirements. Add your logic inside a plugin and remove sizes via this hook.

 // the hook in core
 $sizes = apply_filters( 'intermediate_image_sizes_advanced', $sizes );

A small example to remove the resize for mediumsize.

add_filter( 'intermediate_image_sizes_advanced', 'fb_filter_image_sizes');
function fb_filter_image_sizes( $sizes) {

    unset( $sizes['thumbnail']);

    return $sizes;
}