I have a blog on wordpress.com in which I make use of the Twenty Ten theme. For each Post I can set a Featured image.
On Wordpress.com that image is then displayed in the header above the menu.
I'd like to gain the same for a Wordpress.org setup. How can I do this?
Not sure I understand your question completely hakre but here is the code that shows the featured image for twenty-ten in header.php.The image sizing is defined in the functions.php file.
It also uses a function called http://codex.wordpress.org/Function_Reference/get_header_image.
<?php
// Check if this is a post or page, if it has a thumbnail, and if it's a big one
if ( is_singular() && current_theme_supports( 'post-thumbnails' ) &&
has_post_thumbnail( $post->ID ) &&
( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'post-thumbnail' ) ) &&
$image[1] >= HEADER_IMAGE_WIDTH ) :
// Houston, we have a new header image!
echo get_the_post_thumbnail( $post->ID );
elseif ( get_header_image() ) : ?>
<img src="<?php header_image(); ?>" width="<?php echo HEADER_IMAGE_WIDTH; ?>" height="<?php echo HEADER_IMAGE_HEIGHT; ?>" alt="" />
<?php endif; ?>
$image[1] >= HEADER_IMAGE_WIDTH.