<?php
$string = "[img image:left]1.jpg[/img]Example Text 1[img image:left]2.jpg[/img] Example Text 2";
$string = preg_replace("/\[img\s*[^\]]+\s*\](.*?)\[\/\s*img\]/i", ' \1 ', $string); echo $string;
PD9waHAKJHN0cmluZyA9ICJbaW1nIGltYWdlOmxlZnRdMS5qcGdbL2ltZ11FeGFtcGxlIFRleHQgMVtpbWcgaW1hZ2U6bGVmdF0yLmpwZ1svaW1nXSBFeGFtcGxlIFRleHQgMiI7CiRzdHJpbmcgPSBwcmVnX3JlcGxhY2UoIi9cW2ltZ1xzKlteXF1dK1xzKlxdKC4qPylcW1wvXHMqaW1nXF0vaSIsICcgXDEgJywgJHN0cmluZyk7CmVjaG8gJHN0cmluZzs=