Image tool saves with wrong permissions

My client wants to use the image tool for cropping and scaling. The tools works nice, but saving causes the file permissions to change from 644 to 600, so the scaled images don’t show up in media library anymore and the images are not usable. What can I do for the tool saving with wrong permissions? Sure I can change the permissions on server but that is not an option. Is there a function that solves the permissions on saving from image tool?

Thank you for any info.