protected function createEmptyCanvas($width, $height, $rgb, $real)
    {
        $width  = $this->width  ?? $width;
        $height = $this->height ?? $height;
        $rgb    = $this->color  ?? $rgb;
        $real   = $this->real   ?? $real;

        $this->imageSize = [$width, $height];

        if( $real === false )
        {
            $this->canvas = imagecreate($width, $height);
        }
        else
        {
            $this->canvas = imagecreatetruecolor($width, $height);
        }

        if( ! empty($rgb) )
        {
            $this->allocate($rgb);
        }
    }