filter featured image width and height

functions.php

add_filter( 'et_pb_index_blog_image_width', 'featured_image_width_filter', 100 );
function featured_image_width_filter( $val )
{
    // single page featured image
    if ( is_single() )
    {
        return 625;
    }

    // post box image in blog feed
    return 420;
}

 add_filter( 'et_pb_index_blog_image_height', 'featured_image_height_filter', 100 );
 function featured_image_height_filter( $val )
 {
     return 0;
 }