code: public function getPath($postfix = null)
      {
          $url = sprintf('/%s/', $this->uuid);
          if ($this->default_effects) {
              $url = sprintf('%s-/%s', $url, $this->default_effects);
          }
          if ($this->filename && $postfix === null) {
              $postfix = $this->filename;
          }
  
          $operations = array();
  
          foreach ($this->operations as $i => $operation_item) {
              $part = array();
              foreach (array_keys($operation_item) as $operation_type) {
                  $operation_params = $operation_item[$operation_type];
                  $part[] = $operation_type;
  
                  switch ($operation_type) {
                      case 'crop':
                          $part = $this->__addPartSize($part, $operation_params);
                          $part = $this->__addPartCenter($part, $operation_params);
                          $part = $this->__addPartFillColor($part, $operation_params);
                          break;
                      case 'resize':
                          $part = $this->__addPartSize($part, $operation_params);
                          break;
                      case 'scale_crop':
                          $part = $this->__addPartSize($part, $operation_params);
                          $part = $this->__addPartCenter($part, $operation_params);
                          break;
                      case 'effect':
                          $part = $this->__addPartEffect($part, $operation_params);
                          break;
                      case 'preview':
                          $part = $this->__addPartSize($part, $operation_params);
                          break;
                      case 'custom':
                          $part = array($operation_params);
                          break;
                  }
                  $part_str = join('/', $part);
                  $operations[] = $part_str;
              }
          }
  
          if (count($operations)) {
              $operations_part = join('/-/', $operations);
              return $url.'-/'.$operations_part.'/'.$postfix;
          } else {
              return $url.$postfix;
          }
      }
docs: Get local URL path of original image
  
  @param string $postfix
  @return string