Remove unneeded images / thumbnail sizes

Adding some or all of these lines of code to the functions.php of your wordpress theme will effectively remove some of the default images sizes that may be unneeded. Make sure to include both the _w _h for width and height,

   update_option( 'thumbnail_size_h', 0 );
    update_option( 'thumbnail_size_w', 0 );
    update_option( 'medium_size_h', 0 );
    update_option( 'medium_size_w', 0 );
    update_option( 'large_size_h', 0 );
    update_option( 'large_size_w', 0 );