Lo primero que debes realizar es definir los tamaños de las imágenes en el functions.php de tu theme
if (function_exists('add_theme_support')) { add_theme_support('post-thumbnails'); add_image_size('imagenportada', 620, 310, true); }
Para mostrar las miniaturas en el home:
$Noticias = get_posts(array( 'posts_per_page' => 3, //cantidad 'offset' => 0, 'category' => '24',//categoria 'orderby' => 'post_date', 'order' => 'DESC', 'include' => '', 'exclude' => '', 'meta_key' => '', 'meta_value' => '', 'post_type' => 'post', 'post_mime_type' => '', 'post_parent' => '', 'post_status' => 'publish', 'suppress_filters' => true) ); $i = 0; foreach ($Noticias as $post) : setup_postdata($post); $image = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID), 'imagenportada'); ?>![]()