Add a Copyright Field to the Media Uploader in WordPress

function.php

<?php
/**
 * Adding a "Copyright" field to the media uploader $form_fields array
 *
 * @param array $form_fields
 * @param object $post
 *
 * @return array
 */
function add_copyright_field_to_media_uploader( $form_fields, $post ) {
	$form_fields['copyright_field'] = array(
		'label' => __('Copyright'),
		'value' => get_post_meta( $post->ID, '_custom_copyright', true ),
		'helps' => 'Set a copyright credit for the attachment'
	);

	return $form_fields;
}
add_filter( 'attachment_fields_to_edit', 'add_copyright_field_to_media_uploader', null, 2 );

/**
 * Save our new "Copyright" field
 *
 * @param object $post
 * @param object $attachment
 *
 * @return array
 */
function add_copyright_field_to_media_uploader_save( $post, $attachment ) {
	if ( ! empty( $attachment['copyright_field'] ) ) 
		update_post_meta( $post['ID'], '_custom_copyright', $attachment['copyright_field'] );
	else
		delete_post_meta( $post['ID'], '_custom_copyright' );

	return $post;
}
add_filter( 'attachment_fields_to_save', 'add_copyright_field_to_media_uploader_save', null, 2 );

/**
 * Display our new "Copyright" field
 *
 * @param int $id
 *
 * @return array
 * @usages [show_img_with_copyright id=63]
 */
function get_featured_image_copyright( $atts ) {
    extract(shortcode_atts(array(
        'id' => '',
    ), $atts));

	$attachment_id = ( empty( $id ) ) ? get_post_thumbnail_id() : (int) $id;

	if ( $attachment_id ){
		$output = "<div class='img-wrapper'>";		 
		 $output .= "<img src='".wp_get_attachment_url($attachment_id)."'>";
		 $output .= "<span>".get_post_meta( $attachment_id, '_custom_copyright', true )."</span>";
		$output .= "</div>";
		return $output;
	}

}
add_shortcode( 'show_img_with_copyright', 'get_featured_image_copyright' );

Usages [show_img_with_copyright id=63]