Pop\Image\Gd::resizeToWidth PHP Method

    public function resizeToWidth($wid)
    {
        $scale = $wid / $this->width;
        $hgt = round($this->height * $scale);
        // Create a new image output resource.
        $this->createResource();
        $this->output = imagecreatetruecolor($wid, $hgt);
        // Copy newly sized image to the output resource.
        $this->copyImage($wid, $hgt);
        return $this;
    }