Cropping images from top center using Jetpack Photon

We discussed about this issue in the WordPress.org support forums. Here is a code that should do the trick:

/* 
 * Let's add support for Photon - that won't be necessary once Jetpack 2.3.2 is out. 
 * You'll be able to use apply_filters( 'jetpack_photon_url'... directly
 * See http://jetpack.me/2013/07/11/photon-and-themes/
 */
if( function_exists( 'jetpack_photon_url' ) ) {
    add_filter( 'jetpack_photon_url', 'jetpack_photon_url', 10, 3 );
}

/* 
 * Let's add resized post thumbnails
 * We use a different size on single pages
 */
function jeherve_display_custom( $content, $post ) {
    global $post;

    // If you didn't define a post thumnail, let's forget about all this
    if ( !has_post_thumbnail( $post->ID ) )
        return $content;

    // What's the cropping and the size of image we should use on Single pages? Here we crop to top center and create a 500 x 500px image
    // See http://developer.wordpress.com/docs/photon/api/#crop for parameters
    if ( is_single() ) {
        $args = array(
            'crop'   => '30,0,40,50',
            'resize'   => '500,500',
        );
    }
    // resizing on other pages - some random resizing here
    else {
        $args = array(
            'resize'   => '200,400',
        );
    }

    // Let's create a Photon Image URL from the Post Thumbnail
    $feat_image_url = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'full');
    $photon_image_url = jetpack_photon_url( $feat_image_url[0], $args );

    // Let's build the image tag, as it was built before in your example
    $our_image = sprintf( '<div class="post-media"><a class="featured-image" href="https://wordpress.stackexchange.com/questions/106607/%1$s" title="%2$s"><img src="%3$s" class="wp-post-image" alt="Featured Image"></a></div>',
        esc_url( get_permalink() ),
        esc_attr( sprintf( __( 'Open %s', 'dot' ), get_the_title() ) ),
        esc_attr( $photon_image_url )
    );

    // Let's return the image, right before the post content
    return $our_image . $content;

}
add_filter( 'the_content', 'jeherve_display_custom' );

Here is an example, with the single page crop mentioned above:

• Original Grid image
• Smaller image using the arguments I noted above

For reference, you can check the Photon API documentation available here.