Disable Default Image Crop Sizes

Hi,

When I upload mediafiles, I would like them to be cut only in sizes that I specified through functions.php, to prevent making files I will never use
By default WordPress also cuts sizes to default values specified in wp-admin Settings->Media, here:

screenshot

What I do is set up every size to 0.
However it doesn’t completely solve problem – big images will still be cut to 1200×2400 size, sometimes files are also cut to 0x0 0-byte images.

Is there a good stable solution to somehow ‘unregister’ those default image-crop sizes?