code: public function pixelate( $width, $height, $region = null )
      {
          $size = ceil( max( $width, $height ) / 42 );
  
          if ( $region === null )
          {
              $region = array(
                  'x' => 0,
                  'y' => 0,
                  'w' => $width,
                  'h' => $height
              );
          }
  
          $tmpRegion = array(
              'x' => $region['x'],
              'y' => $region['y'],
              'w' => $size,
              'h' => $size
          );
  
          $activeReference = $this->getActiveReference();
          $blur = ( $size * 3 ) . 'x' . ( $size * 4 );
  
          $i = $region['x'];
  
          $i_max = $region['w'] + $region['x'];
          $j_max = $region['h'] + $region['y'];
  
          for ( ; $i < $i_max; $i += $size )
          {
              $tmpRegion['x'] = $i;
  
              $j = $region['y'];
              for ( ; $j < $j_max; $j += $size )
              {
                  $tmpRegion['y'] = $j;
  
                  $this->setRegion( $tmpRegion );
  
                  $this->addFilterOption( $activeReference,
                      '-blur',
                      $blur
                  );
              }
          }
      }
docs: /* (non-PHPdoc)
  @see extension/ezie/autoloads/eziezc/interfaces/eZIEEzcConversions#pixelate($width, $height, $region)