Actually in the end, I found it much easier for the task to be done in Python using the following code:
import urllib
f = urllib.urlopen("URL")
s = f.read()
f.close()
from bs4 import BeautifulSoup
soup = BeautifulSoup(s)
inputTags = soup.find_all("img", attrs={"src":True})
output = [ x["src"] for x in inputTags ]
print output
And yep I know this is C# forum! :D