Set default attachment display settings, alignment, link to, size in wordpress

functions.php

<?php

/*
 * Set default attachment display settings, alignment, link to, size in wordpress
 * @Url http://wpsnipp.com/index.php/functions-php/set-default-attachment-display-settings-alignment-link-size-wordpress/
 */

function wps_attachment_display_settings() {
        update_option( 'image_default_align', 'left' );
        update_option( 'image_default_link_type', 'none' );
        update_option( 'image_default_size', 'large' );
}
add_action( 'after_setup_theme', 'wps_attachment_display_settings' );