Reduce the size of the header on a SharePoint page

What is the best way to reduce the size of the image header on a modern SharePoint page?

This is what it's like out of the box, but we find it takes up too much space on the page.  Going without the image altogether is not a preferred option. 

Ideally we'd like to be able to reduce the depth of the header section, like this:

What is the best way of doing this?

Hope someone can help.