Hello
Yes, the header area can be made transparent so the background image will show through.
In the customizer, go to ‘Header and Menu Styling’ and in the setting for ‘Header Background Color’ slide the transparency setting all the way to the left to 0 (zero).
Setting this to zero will make the header transparent across the whole site.
If you want a transparent header only on the homepage, set your preferred background color (for the whole of your site) as above, and then add this CSS to ‘Additional CSS’:
.home #masthead{
background: transparent;
}