Wordpress - Responsive images - remove sizes

Question

Sometime ago I added a couple of additional image formats to Wordpress in order to fine-tune my responsive display. I added those lines to functions.php:

add_image_size( "maximal", "1900" );
add_image_size( "desktop", "1400" );
add_image_size( "tablet", "900" );
add_image_size( "smalltablet", "700" );
add_image_size( "mobile", "500" );
add_theme_support( 'post-thumbnails' ); 

I release I was too greedy because I'm not using most of those formats now and I would like to remove some of them. To do so I basically commented the image formats that I wanted to get rid of but from what I see, all srcset attributes are still listing them in my code.

Is there a way to tell Wordpress to stop adding those formats in srcset ? I thought of using a regex to get rid of them but that generates additional processing to the page.

Thanks

Laurent

Answer 1

To make sure that these images' sizes is unregistered use this:

remove_image_size( "maximal" );

Then use these filters to clean the current images from these sizes:

// Remove the calculated image sizes
add_filter( 'wp_calculate_image_sizes', '__return_false' );

// Remove the calculated image sizes
add_filter( 'wp_calculate_image_srcset', '__return_false' );

// Clean image attrs
add_filter( 'wp_get_attachment_image_attributes', 'unset_image_sizes');
function unset_image_sizes() {
  if( isset( $attr['sizes'] ) )
    unset( $attr['sizes'] );

  if( isset( $attr['srcset'] ) )
    unset( $attr['srcset'] );
}

I hope this helps.