intermediate_image_sizes_advanced

add_filter( ‘intermediate_image_sizes_advanced’, ‘hoge_remove_default_images’ ); function hoge_remove_default_images( $sizes ) { unset( $sizes[‘small’]); // 150px unset( $sizes[‘medium’]); // 300px unset( $sizes[‘large’]); // 1024px unset( $sizes[‘medium_large’]); // 768px return $sizes; }