How to crop uploaded images instead of scaling them

Just add the code below to your functions.php file:

// Standard Size Thumbnail
if(false === get_option("thumbnail_crop")) {
     add_option("thumbnail_crop", "1"); }
     else {
          update_option("thumbnail_crop", "1");
     }

// Medium Size Thumbnail
if(false === get_option("medium_crop")) {
     add_option("medium_crop", "1"); }
     else {
          update_option("medium_crop", "1");
     }

// Large Size Thumbnail
if(false === get_option("large_crop")) {
     add_option("large_crop", "1"); }
     else {
          update_option("large_crop", "1");
      }

Thanks to wp-snippet.com for the tip!