How would I use a filter to remove header banner on certain post types

Question

I am using a child theme of twenty-twelve, and want to remove the huge banner image in the header for certain post types. How can I use add_filter() or add_action() to do this? I don't want to mess with the header.php file in the parent theme, I just want to preg_replace the HTML content that the header has. Excuse my ignorance, but I am fairly not versed in WP yet.

Answer 1

Copy header.php to your child theme so you're not editing the parent theme's file. And on line 49, you will see this line of code:

if ( ! empty( $header_image ) ) : ?>

This says if header image is not empty show the header image. So you can add to that condition to check for any post type you want. Like this example:

if ( ! empty( $header_image ) && get_post_type() !== 'my-posttype' ) : ?>