How to remove header images from displaying (not css or editing)?

Question

I removed/unregistered the theme (BirdTIPS) header images, but the default header image is still displayed. How to remove it programmatically (not css or editing header.php)?

My code:

add_action( 'after_setup_theme', 'remove_default_headers', 11 );

function remove_default_headers() {
    remove_theme_support( 'custom-header', array(
        'default-image',
    ) );
    unregister_default_headers(
        array(
            'green',
            'blue',
            'yellow',
            'red',
            'white',
            'orange',
            'pink',
            'purple'
        )
    );
}

In the header block of the header.php there is this code (I want to avoid to edit it, nor in the child theme):

    <?php if ( ! empty( $birdtips_header_image ) ) : ?>
            <?php if ( 'blank' == get_header_textcolor() ): ?>
                <a href="<?php echo home_url( '/' ); ?>"><img src="<?php header_image(); ?>" alt="<?php bloginfo( 'name' ); ?>" ></a>
            <?php else: ?>
                <img src="<?php header_image(); ?>" alt="<?php bloginfo( 'name' ); ?>" >
            <?php endif; ?>
    <?php endif; ?>

Answer 1

As You have stated in comment that You have disabled header images, but its still returning default image.

Explanation : It depends on how it was coded in the theme by the developer. For an instance, it seems like if you disable all header images, it returns Default header set by the developer / theme.

Now, Even if the function header_image() doesn't returns anything, <img> tag will be there and a placeholder or Alt Text will appear on the page, that is not a proper solution/way to remove header.

Answer 2

Yes, unfortunately, it looks like you'll have to edit the header.php and remove the tag from there. Even if you disable the default image on there, the image tag will still show in your html.

Since you're using a child theme, what's the risk of editing your child theme's header.php?