WordPress at a glance
filter is not described

wp_get_attachment_image_attributes filter-hook . WP 2.8.0

Filters the list of attachment image attributes.


add_filter( 'wp_get_attachment_image_attributes', 'filter_function_name_1637', 10, 3 );
function filter_function_name_1637( $attr, $attachment, $size ){
	// filter...

	return $attr;
Attributes for the image markup.
Image attachment post.
Requested size. Image size or array of width and height values (in that order).
Default: 'thumbnail'

Where the hook is called

wp-includes/media.php 920
$attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, $attachment, $size );

Where the hook is used (in WP core)

wp-includes/media.php 1469
add_filter( 'wp_get_attachment_image_attributes', '_wp_post_thumbnail_class_filter' );
wp-includes/media.php 1482
remove_filter( 'wp_get_attachment_image_attributes', '_wp_post_thumbnail_class_filter' );