the images lack contrast , are murky and are frequently too dark to be decipherable . 
(ROOT (S (NP (DT the) (NNS images)) (VP (VP (VBP lack) (NP (NN contrast))) (, ,) (VP (VBP are) (ADJP (JJ murky))) (CC and) (VP (VBP are) (ADVP (RB frequently)) (ADJP (RB too) (JJ dark) (SBAR (S (VP (TO to) (VP (VB be) (ADJP (JJ decipherable))))))))) (. .)))
(ROOT (S (NP (DT ) (NNS )) (VP (VP (VBP ) (NP (NN ))) (, ) (VP (VBP ) (ADJP (JJ ))) (CC ) (VP (VBP ) (ADVP (RB )) (ADJP (RB ) (JJ ) (SBAR (S (VP (TO ) (VP (VB ) (ADJP (JJ ))))))))) (. )))