EasyImage::watermark PHP Method

    public function watermark($watermark, $offset_x = null, $offset_y = null, $opacity = 100)
    {
        if ($watermark instanceof EasyImage) {
            $watermark = $watermark->image();
        } elseif (is_string($watermark)) {
            $watermark = Image::factory(Yii::getpathOfAlias('webroot') . $watermark);
        }
        return $this->image()->watermark($watermark, $offset_x, $offset_y, $opacity);
    }

 /**
  * Add Watermark to existing image
  * @param string $imagePath
  * @param string $watermarkPath
  * @param integer $offsetX
  * @param integer $offsetY
  * @param integer $opacity
  * @return boolean true if image success add watermark false otherwise
  */
 public static function watermark($imagePath, $watermarkPath, $offsetX = null, $offsetY = null, $opacity = 100)
 {
     $status = false;
     if (file_exists($imagePath) && file_exists($watermarkPath)) {
         $watermark = new EasyImage($watermarkPath);
         $image = new EasyImage($imagePath);
         $image->watermark($watermark, $offsetX, $offsetY, $opacity);
         $status = $image->save();
     }
     return $status;
 }