custom-header on specific template(s)/pages

How can I set theme support custom-header on a per page basis, i don’t want 600 custom header.php implementations just need to be able to set a specific header image on specific page templates

so when the page template is “my-custom-page” I want to set a custom header image, when the page template is “my-cutom-page2” I want to set another header image

i don’t want a great big if, nor a plugin, I need a code sample then will allow me to set a header image based on the page template, I can then use this to create a dynamic process.