add_filter('wp_handle_upload_prefilter','custom_upload_filter' );
function custom_upload_filter( $file ){
    $file['name'] = 'wordpress-is-awesome-' . $file['name'];
    return $file;
}

按照上面的说法挂钩上传操作,并做一些像生成额外的图像：

function generate_image($src_file,$dst_file) {
     $src_img = imagecreatefromgif($src_file);
     $w = imagesx($src_img);
     $h = imagesy($src_img);

     $new_width = 520;
     $new_height = floor($new_width * $h / $w);

     if(function_exists("imagecopyresampled")){
         $new_img = imagecreatetruecolor($new_width,$new_height);
         imagealphablending($new_img,false);
         imagecopyresampled($new_img,$src_img,$new_width,$new_height,$w,$h);
     } else {
         $new_img = imagecreate($new_width,false);
         imagecopyresized($new_img,$h);
     }
     imagesavealpha($new_img,true);    
     imagejPEg($new_img,$dst_file);

     imageDestroy($src_img);
     imageDestroy($new_img);

     return $dst_file;
}