wp_create_thumbnail filter-hook . WP 1.2.0

Deprecated in 3.5.0. It is no longer supported and can be removed in future releases. Use image_resize() instead.

This was once used to create a thumbnail from an Image given a maximum side size.

Usage

add_filter( 'wp_create_thumbnail', 'filter_function_name_2309' );
function filter_function_name_2309( $file ){
	// filter...

	return $file;
}

$file(mixed)

Filename of the original image, Or attachment id.

Where the hook is called

return apply_filters( 'wp_create_thumbnail', image_resize( $file, $max_side, $max_side ) );

Where the hook is used (in WP core)