Image_GD::_load_image PHP Method

    protected function _load_image()
    {
        if (!is_resource($this->_image)) {
            // Gets create function
            $create = $this->_create_function;
            // Open the temporary image
            $this->_image = $create($this->file);
            $this->_set_interlacing($this->_image);
            // Preserve transparency when saving
            imagesavealpha($this->_image, TRUE);
        }
    }