nilsteampassnet / TeamPass

        {

            // Gray image

            $len = 2 * $w;

            for ($i = 0; $i < $h; $i++)

            {

                $pos = (1 + $len) * $i;

                $color .= $data[$pos];

                $alpha .= $data[$pos];

                $line = substr($data, $pos + 1, $len);

                $color .= preg_replace('/(.)./s', '$1', $line);

                $alpha .= preg_replace('/.(.)/s', '$1', $line);

            }

        } else

        {

            // RGB image

        {

            // RGB image

            $len = 4 * $w;

            for ($i = 0; $i < $h; $i++)

            {

                $pos = (1 + $len) * $i;

                $color .= $data[$pos];

                $alpha .= $data[$pos];

                $line = substr($data, $pos + 1, $len);

                $color .= preg_replace('/(.{3})./s', '$1', $line);

                $alpha .= preg_replace('/.{3}(.)/s', '$1', $line);

            }

        }

        unset($data);

        $data = gzcompress($color);